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Summary of Significant Accounting Policies (Estimated Fair Value and Carrying Value of Notes) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Estimated Fair Value [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Notes payable	$ 16,038	$ 15,915
Carrying Value [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Notes payable	$ 15,871	$ 14,659

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current assets
Cash and cash equivalents	$ 29,627	$ 18,844
Investments	19,472	83,510
Accounts receivable	15,266	8,595
Inventory	13,312	17,878
Prepaid expenses and other current assets	3,369	2,832
Total current assets	81,046	131,659
Property and equipment, net	30,070	34,073
Operating lease right-of-use assets, net	32,827
Long-term restricted cash	4,000	4,500
Other long-term assets	42	43
Total assets	147,985	170,275
Current liabilities
Accounts payable	8,368	6,736
Accrued expenses	13,242	12,823
Deferred revenue, current	7,610	6,537
Operating lease liabilities, current	3,837
Notes payable, current	15,871
Other liabilities, current	225	788
Total current liabilities	49,153	26,884
Deferred revenue, non-current	1,951	890
Operating lease liabilities, non-current	41,964
Deferred rent, non-current		13,765
Notes payable, non-current		14,659
Financing derivative		16
Total liabilities	93,068	56,214
Commitments and contingencies
Stockholders' equity
Preferred stock, $0.001 par value: Authorized 50,000 shares; No shares issued or outstanding
Common stock, $0.001 par value: Authorized 1,000,000 shares; issued and outstanding 153,119 and 150,244 shares at December 31, 2019 and December 31, 2018, respectively	153	150
Additional paid-in capital	1,120,999	1,096,053
Accumulated other comprehensive income (loss)	5	(36)
Accumulated deficit	(1,066,240)	(982,106)
Total stockholders' equity	54,917	114,061
Total liabilities and stockholders' equity	$ 147,985	$ 170,275

Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	At the Market Offering [Member] Common Stock	At the Market Offering [Member] Additional Paid-in Capital [Member]	At the Market Offering [Member]	Underwritten Public Equity Offering [Member] Common Stock	Underwritten Public Equity Offering [Member] Additional Paid-in Capital [Member]	Underwritten Public Equity Offering [Member]	Common Stock	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Deficit [Member]	Total
Balance at Dec. 31, 2016							$ 93	$ 872,114	$ 5	$ (787,544)	$ 84,668
Balance, shares at Dec. 31, 2016							92,677
Net loss										(92,189)	(92,189)
Other comprehensive income (loss)									(37)		(37)
Issuance of common stock in conjunction with equity plans							$ 2	8,912			8,914
Issuance of common stock in conjunction with equity plans, shares							2,697
Issuance of common stock from offering, net of issuance costs	$ 3	$ 11,862	$ 11,865	$ 18	$ 52,512	$ 52,530
Issuance of common stock from offering, net of issuance costs, shares	3,171		3,200	17,732
Stock-based compensation expense								20,352			20,352
Balance at Dec. 31, 2017							$ 116	965,752	(32)	(879,733)	86,103
Balance, shares at Dec. 31, 2017							116,277
Net loss										(102,562)	(102,562)
Other comprehensive income (loss)									(4)		(4)
ASC606 adoption effect										189	189
Issuance of common stock in conjunction with equity plans							$ 4	9,648			9,652
Issuance of common stock in conjunction with equity plans, shares							3,357
Issuance of common stock from offering, net of issuance costs				$ 30	$ 97,500	$ 97,530
Issuance of common stock from offering, net of issuance costs, shares				30,610		30,600
Stock-based compensation expense								23,153			23,153
Balance at Dec. 31, 2018							$ 150	1,096,053	(36)	(982,106)	$ 114,061
Balance, shares at Dec. 31, 2018							150,244				150,244
Net loss										(84,134)	$ (84,134)
Other comprehensive income (loss)									41		41
Issuance of common stock in conjunction with equity plans							$ 3	8,545			8,548
Issuance of common stock in conjunction with equity plans, shares							2,875
Stock-based compensation expense								16,401			16,401
Balance at Dec. 31, 2019							$ 153	$ 1,120,999	$ 5	$ (1,066,240)	$ 54,917
Balance, shares at Dec. 31, 2019							153,119				153,119

Stockholders' Equity (Summary of Stock Option Activity) (Details) - Options outstanding [Member] - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of shares, Options granted
Exercise price, lower range
Weighted average exercise price, Options granted
$1.16 – 16.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of shares, Balances, December 31, 2018	25,176
Number of shares, Balances, December 31, 2019	22,697	25,176
Exercise price, lower range	$ 1.16	$ 1.16
Exercise price, upper range	16.00	16.00
Weighted average exercise price, Balances, December 31, 2018	5.66
Weighted average exercise price, Balances, December 31, 2019	$ 5.57	$ 5.66
$1.16 – 7.05 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of shares, Options exercised	(1,199)
Exercise price, lower range	$ 1.16
Exercise price, upper range	7.05
Weighted average exercise price, Options exercised	$ 4.78
$2.54 – 16.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of shares, Options canceled	(1,280)
Exercise price, lower range	$ 2.54
Exercise price, upper range	16.00
Weighted average exercise price, Options canceled	$ 8.01

Termination of Merger with Illumina	12 Months Ended
Termination of Merger with Illumina	Dec. 31, 2019
Termination of Merger with Illumina [Abstract]
Termination of Merger with Illumina	NOTE 2. TERMINATION OF MERGER WITH ILLUMINA On November 1, 2018, we entered into a Merger Agreement with Illumina and FC Ops Corp. We, Illumina and Merger Subsidiary entered into the Amendment on September 25, 2019. The Amendment, among other things, extended the End Time (as defined in the Merger Agreement) to December 31, 2019. Additionally, Illumina had until December 18, 2019 to exercise its unilateral right to extend the End Time to March 31, 2020. In addition, the Amendment provided that Illumina would make payments to us of $6.0 million on or before each of October 1, 2019, November 1, 2019 and December 2, 2019. If Illumina elected to further extend the End Time to March 31, 2020, then, except under limited situations, Illumina would be required to make payments to us of $6.0 million on or before each of January 2, 2020, and March 2, 2020, and a payment of $22.0 million on or before February 3, 2020. On December 17, 2019, the U.S. Federal Trade Commission publicly announced that it had authorized legal action to block the Merger. On December 18, 2019, we received written notice from Illumina pursuant to which Illumina exercised its right under Section 10.01(b)(i) of the Merger Agreement, to extend the End Time to March 31, 2020. In accordance with the terms of the Merger Agreement , we received Continuation Advances totaling $18.0 million from Illumina during the fourth quarter of 2019, which are reflected in the “Gain from Continuation Advances from Illumina” line in the consolidated statements of operations and comprehensive loss for the year ended December 31, 2019. On January 2, 2020, we, Illumina and Merger Subsidiary entered into the Termination Agreement to terminate the Merger Agreement. As part of our agreement to terminate the Merger Agreement, Illumina subsequently paid us the Reverse Termination Fee from which we expect to pay our financial advisor associated fees of approximately $10 million. In addition, Illumina paid us the additional Continuation Advances of $6 million in January 2020 and $22 million in February 2020 and is scheduled to make a final Continuation Advance to us of $6 million in March 2020. However, pursuant to the Termination Agreement, in the event that, on or prior to September 30, 2020, we enter into a definitive agreement providing for, or consummate, a Change of Control Transaction (as defined in the Termination Agreement), then we will repay the Reverse Termination Fee (without interest) to Illumina in connection with the consummation of such Change of Control Transaction. If such Change of Control Transaction is not consummated by the two-year anniversary of the execution of the definitive agreement for such Change of Control Transaction, then we will not be required to repay the Reverse Termination Fee. In addition, up to the full amount of the Continuation Advances paid to us are repayable without interest to Illumina if, within two years of March 31, 2020, we enter into a Change of Control Transaction or raise at least $100 million in equity in a single transaction or debt financing (that may have multiple closings), with the amount repayable dependent on the amount raised by us. Please refer to “Note 3 Summary of Significant Accounting Policies” for additional accounting considerations relating to the Continuation Advances received.

Income Taxes (Reconciliation of Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Net operating loss carryforwards	$ 226,911	$ 212,424
Research and development credits	45,853	42,635
Accruals and reserves	8,024	4,774
Stock-based compensation	16,219	14,582
Deferred rent		3,315
ASC842 Operating lease liability	10,837
Total deferred tax assets	307,844	277,730
Less: Valuation allowance	(298,658)	(275,540)
Total deferred tax assets:	9,186	2,190
Fixed assets	(1,425)	(2,190)
ASC842 Operating Lease right-of-use assets	(7,761)
Total deferred tax liabilities	(9,186)	(2,190)
Net deferred tax assets

Stockholders' Equity

12 Months Ended

Dec. 31, 2019

Stockholders' Equity [Abstract]

Stockholders' Equity

NOTE 9. STOCKHOLDERS’ EQUITY

Preferred Stock

Our Certificate of Incorporation, as amended and restated in October 2010 in connection with the closing of our initial public offering, authorizes us to issue 1,000,000,000 shares of $0.001 par value common stock and 50,000,000 shares of $0.001 par value preferred stock. As of December 31, 2019 and 2018, there were no shares of preferred stock issued or outstanding.

Common Stock

Common stockholders are entitled to dividends when and if declared by our board of directors. There have been no dividends declared to date. The holder of each share of common stock is entitled to one vote.

“At-the-Market” Offering

For the year ended December 31, 2017, we issued 3.2 million shares of our common stock at an average price of $3.86 per share through our “at-the-market” offering program, resulting in net proceeds of $11.9 million.

We terminated our “at-the-market” offering program in June 2017. We paid a commission equal to 3% of the gross proceeds from the sale of shares of our common stock under the sales agreement.

Underwritten Public Equity Offerings

In August 2017, we filed a shelf registration statement on Form S-3 with the SEC pursuant to which we may, from time to time, sell up to an aggregate of $150.0 million of our common stock, preferred stock, depository shares, warrants, units or debt securities. On August 18, 2017, the registration statement was declared effective by the SEC, which allows us to access the capital markets for the three-year period following this effective date.

In June 2017, we issued and sold a total of 17.7 million shares of our common stock at a price to the public of $3.10 per share in an underwritten public offering. We paid a commission equal to 4% of the gross proceeds from the sale of shares of our common stock under the underwriting agreement. The total proceeds to us from the offering, after deducting the underwriting commission and offering expenses, were approximately $52.5 million.

For the year ended December 31, 2018, we issued 30.6 million shares of our common stock through our two underwritten public offerings with an average offering price of $3.38 per share. The total net proceeds to us from the two offerings, after deducting the underwriting commissions and offering expenses, were approximately $97.5 million.

Subject to certain exceptions set forth in the Facility Agreement, holders of our Notes may elect to receive up to 25% of the net proceeds from financing activities that include an equity component as prepayment of the Notes to be applied first, to accrued and unpaid interest and second, to principal. However, in both February 2018 and September 2018, holders representing a majority of the aggregate principal amount of the outstanding Notes waived such right in connection with the issuance and sale of shares of common stock in our public offering. In June 2017, pursuant to a partial exercise by the Notes holders of this right, we repaid $4.5 million of outstanding principal, together with accrued and unpaid interest, to one of the Notes holders with proceeds from our underwritten public equity offering.

Equity Plans

As of December 31, 2019, we had two active equity plans: 1) the 2010 Equity Incentive Plan or “2010 Plan” and 2) the 2010 Outside Director Equity Incentive Plan or “2010 Director Plan”, both of which we adopted upon the effectiveness of our initial public offering in October 2010. The 2010 Employee Stock Purchase Plan or “2010 ESPP Plan” was terminated after the completion of the purchase period ended March 1, 2019. Prior to the adoption of these plans, we granted options pursuant to the 2004 Equity Incentive Plan and 2005 Stock Plan. Upon termination of the predecessor plans, the shares available for grant at the time of termination and shares subsequently returned to the plans upon forfeiture or option termination, were transferred to the successor plan in effect at the time of share return. Under the 2010 Plan, with the approval of the Compensation Committee of the Board of Directors, we may grant restricted stock, Restricted Stock Units (“RSU”), stock appreciation rights and new shares of common stock upon exercise of stock options.

2010 Equity Incentive Plan and Outside Director Equity Incentive Plan

Stock options granted under the 2010 Plan may be either Incentive Stock Option (“ISO”) or Non-Qualified Stock Option (“NSO”). ISOs may be granted only to employees. NSOs may be granted to employees, consultants and directors. Stock options under the 2010 Plan may be granted with a term of up to ten years and at prices no less than the fair market value of our common stock on the date of grant. To date, stock options granted to existing employees generally vest over four years on a monthly basis and stock options granted to new employee vest at a rate of 25% upon the first anniversary of the vesting commencement date and 1/48th per month thereafter

Stock options granted under the 2010 Director Plan provide for the grant of NSOs. Stock options under the 2010 Plan may be granted with a term of up to ten years and at prices no less than the fair market value of our common stock on the date of grant. To date, stock options granted to existing directors generally vest over one year on a monthly basis and stock options granted to new directors generally vest over three years at a rate of one-third upon the first anniversary of the vesting commencement date and 1/36th per month thereafter.

As of December 31, 2019 and 2018, we had an aggregate of 20.5 million and 11.3 million shares of common stock, respectively, reserved and available for future issuance under the 2010 Plan and 2010 Director Plan.

In January 2020, an additional 7.7 million shares were reserved under the 2010 Plan and an additional 1.5 million shares were reserved under the 2010 Director Plan.

Stock Options

For the year ended December 31, 2019, no stock options were granted. The following table summarizes stock option activity for the year ended December 31, 2019 (in thousands, except per share amounts):



	Stock Options Outstanding
	Number			Weighted average
	of shares	Exercise price		exercise price
Balances, December 31, 2018	25,176	$	1.16 – 16.00	$	5.66
Additional shares reserved
Options granted	—		—		—
Options exercised	(1,199)	$	1.16 – 7.05	$	4.78
Options canceled	(1,280)	$	2.54 – 16.00	$	8.01
Balances, December 31, 2019	22,697	$	1.16 – 16.00	$	5.57

The expired options during the year ended December 31, 2019 totaled 0.9 million with exercise price range from $2.54 to $16.00 and a weighted average exercise price per share of $9.90.

The following table summarizes information with respect to stock options outstanding and exercisable under the plans at December 31, 2019:



		Options Outstanding				Options Exercisable
			Weighted average
		Number	remaining contractual	Weighted average		Number	Weighted average
Exercise price		outstanding	life (Years)	exercise price		vested	exercise price
$	0.00 – 1.60	414,207	2.87	$	1.18	414,207	$	1.18
$	1.60 – 3.20	5,720,080	6.38	$	2.54	3,680,040	$	2.54
$	3.20 – 4.80	3,110,896	3.88	$	4.02	2,858,193	$	4.02
$	4.80 – 6.40	5,935,013	6.12	$	5.46	4,895,635	$	5.46
$	6.40 – 8.00	2,554,434	5.19	$	7.21	2,525,441	$	7.21
$	8.00 – 9.60	3,061,742	4.63	$	8.77	2,938,483	$	8.77
$	9.60 – 11.20	1,224,700	4.94	$	10.20	1,224,700	$	10.20
$	11.20 – 12.80	423,252	1.08	$	12.10	423,252	$	12.10
$	12.80 – 14.40	163,250	1.00	$	13.71	163,210	$	13.71
$	14.40 – 16.00	89,000	0.80	$	15.99	89,000	$	15.99
		22,696,574	5.30	$	5.57	19,212,161	$	5.90

The aggregate intrinsic value of the outstanding and exercisable options presented in the table above totaled $20.0 million and $14.5 million, respectively. The aggregate intrinsic value represents the total pretax intrinsic value (i.e., the difference between $5.14, our closing stock price on the last trading day of our fourth quarter of 2019 and the exercise price, multiplied by the number of in-the-money options) that would have been received by the option holders had all option holders exercised their options on December 31, 2019. The aggregate intrinsic value changes at each reporting date based on the fair market value of our common stock. The weighted average remaining contractual life for exercisable options is 4.86 years.

The vested and expected to vest options as of December 31, 2019 totaled 21,231,000, with aggregate intrinsic value of $17.8 million, weighted average exercise price per share of $5.69 and weighted average remaining contractual life of 5.13 years.

The total intrinsic value of stock options exercised during the years ended December 31, 2019, 2018 and 2017 was $2.6 million, $5.3 million and $1.7 million, respectively.

The total fair value of stock options vested during the years ended December 31, 2019, 2018 and 2017 was $2.9 million, $3.9 million and $6.4 million, respectively.

Time-based RSUs

Beginning in the three months ended March 31, 2018, the Compensation Committee of the Board of Directors has approved awards of RSUs with time-based vesting under the 2010 Plan to certain employees. Each RSU represents one equivalent share of our common stock to be awarded after the vesting period. These RSUs vest over four years at a rate of 25% annually. The fair value for these RSUs is based on the closing price of our common stock on the date of grant. We measure compensation expense for these RSUs at fair value on the date of grant and recognize the expense over the expected vesting period on a straight-line basis. The RSUs do not entitle participants to the rights of holders of common stock, such as voting rights, until the shares are issued. RSUs that are expected to vest are net of estimated future forfeitures.

The following table summarizes the time-based RSUs activity for the year ended December 31, 2019 (in thousands, except per share amounts):


		Weighted average
	Number	grant date
	of shares	fair value
RSUs outstanding at December 31, 2018	371	$	3.20
RSUs granted	900		7.06
RSUs vested	(127)		4.35
RSUs forfeited	(58)		5.86
Unvested RSUs outstanding at December 31, 2019	1,086	$	6.12

For the years ended December 31, 2019, we recognized compensation expense of $4.9 million related to time-based RSUs.

Performance-based RSUs

During 2018, the Compensation Committee of the Board of Directors approved awards of RSUs with performance-based vesting under the 2010 Plan to certain employees. Each RSU represents one equivalent share of our common stock to be awarded upon vesting at the end of the performance periods, if specific performance goals set by the Compensation Committee of the Board of Directors are achieved. No RSUs with performance-based vesting will vest if the performance goals are not met. The fair value of these RSUs is based on the closing price of our common stock on the date of grant. We make a quarterly probability assessment as to whether the performance goals will be achieved. Changes in our assessment of the probability of vesting results in adjustments to stock-based compensation, which may include either a cumulative catch-up of expense or a reduction of expense depending on whether the likelihood of vesting has increased or decreased, that is recognized in the period such determination is made. The RSUs do not entitle participants to the rights of holders of common stock, such as voting rights, until the shares are issued. RSUs that are expected to vest are net of estimated future forfeitures.

The following table summarizes the performance-based RSUs activity for the year ended December 31, 2019 (in thousands, except per share amounts):


		Weighted average
	Number	grant date
	of shares	fair value
PSUs outstanding at December 31, 2018	586	$	2.58
PSUs granted	—		—
PSUs vested	(204)		2.57
PSUs forfeited	(244)		2.57
Unvested PSUs outstanding at December 31, 2019	138	$	2.63

2010 Employee Stock Purchase Plan

We adopted the ESPP in October 2010. Our ESPP permits eligible employees to purchase common stock at a discount through payroll deductions during defined offering periods. Each offering period will generally consist of four purchase periods, each purchase period being approximately six months. The price at which the stock is purchased is equal to the lower of 85% of the fair market value of the common stock at the beginning of an offering period or at the end of a purchase period. Each offering period will generally end and the shares will be purchased twice yearly on March 1 and September 1. If the stock price at the end of the purchase period is lower than the stock price at the beginning of the offering period, that offering period will then be terminated and new offering period comes to place.

For the years ended December 31, 2019, 2018 and 2017, 1,306,329 shares, 1,674,960 shares and 1,289,663 shares of common stock were purchased under the ESPP, respectively. As of December 31, 2019, 3,651,066 shares of our common stock remain available for issuance under our ESPP. Pursuant to the terms of the Merger Agreement, the ESPP was terminated after the completion of the purchase period ended March 1, 2019.

Since the Merger Agreement has been terminated, we will begin offerings under the ESPP again starting with the offering period on March 1, 2020.

The ESPP provides for an annual increase to the shares available for issuance at the beginning of each calendar year equal to 2% of the common shares then outstanding. During January 2020, an additional 3.1 million shares were reserved under the ESPP.

Stock-based Compensation

Total stock-based compensation expense consists of the following (in thousands):



	Years Ended December 31,
	2019		2018		2017
Cost of revenue	$	1,857	$	3,124	$	2,311
Research and development		7,699		10,076		8,506
Sales, general and administrative		6,845		9,953		9,535
Total stock-based compensation expense	$	16,401	$	23,153	$	20,352

As of December 31, 2019 and 2018, $0.3 million and $0.7 million of stock-based compensation cost was capitalized in inventory on our consolidated balance sheets, respectively.

The tax benefit of stock-based compensation expense was immaterial for the years ended December 31, 2019, 2018 and 2017.

Stock Options

We estimated the fair value of employee stock options using the Black-Scholes option pricing model. The fair value of employee stock options is being amortized on a straight-line basis over the requisite service period of the awards. For the year ended December 31, 2019, we did not grant any stock option. For the years ended December 31, 2018 and 2017, the weighted average fair value at grant date per stock option was $1.50 and $3.08, respectively. We recorded stock-based compensation expense for stock options of $11.0 million, $15.5 million and $17.2 million for the years ended December 31, 2019, 2018 and 2017, respectively.

For the years ended December 31, 2019, 2018 and 2017, the fair value of employee stock options was estimated using the following weighted average assumptions:



	Years Ended December 31,
	2019		2018		2017
Expected term (years)		—		5.2 years		6.1 years
Expected volatility		—		66.8%		70.0%
Risk-free interest rate		—		2.6%		2.1%
Dividend yield		—		—		—

As of December 31, 2019, $5.6 million of total unrecognized compensation expense related to stock options was expected to be recognized over a weighted-average period of 1.5 years. Future option grants will increase the amount of compensation expense to be recorded in those future periods.

Cash received from option exercises for the years ended December 31, 2019, 2018 and 2017 was $5.9 million, $6.3 million and $3.6 million, respectively.

ESPP

We estimated the fair value of shares to be issued under the ESPP using the Black-Scholes option pricing model. For the years ended December 31, 2019, 2018 and 2017, weighted average fair value at grant date for shares to be issued under the ESPP was $0, $1.47 and $2.28, respectively. We recorded stock-based compensation expense for ESPP of $0.5 million, $6.8 million and $3.1 million for the years ended December 31, 2019, 2018 and 2017, respectively.

Pursuant to the Merger Agreement, the ESPP was terminated after the completion of the purchase period ended March 1, 2019. As a result, approximately $2.5 million of ESPP expense was accelerated and recognized in the fourth quarter of 2018. In addition, for the year ended December 31, 2019 there were no offerings after March 1, 2019 and as such, there were no new Black-Scholes calculations performed to calculate the fair value of new purchase rights granted for the three months ended March 31, 2019 and for the year ended December 31, 2019.

For the years ended December 31, 2019, 2018 and 2017, the fair value of shares to be issued under the ESPP was estimated using the following assumptions:



	Years Ended December 31,
	2019		2018		2017
Expected term (years)		—		0.5 - 2.0		0.5 - 2.0
Expected volatility		—		65% - 67%		70.0%
Risk-free interest rate		—		1.3%-2.7%		0.8%-1.4%
Dividend yield		—		—		—

Cash received through the ESPP for the years ended December 31, 2019, 2018 and 2017 was $2.7 million, $3.4 million and $5.3 million, respectively.

Stockholders' Equity (Reconciliation of Outstanding and Exercisable Stock Options) (Details) - Options outstanding [Member]	12 Months Ended
	Dec. 31, 2019 $ / shares shares
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise price, lower range
Number outstanding \| shares	22,696,574
Weighted average remaining contractual life (Years)	5 years 3 months 18 days
Weighted average exercise price	$ 5.57
Number vested \| shares	19,212,161
Weighted average exercise price	$ 5.90
$0.00 - 1.60 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise price, lower range	0.00
Exercise price, upper range	$ 1.60
Number outstanding \| shares	414,207
Weighted average remaining contractual life (Years)	2 years 10 months 13 days
Weighted average exercise price	$ 1.18
Number vested \| shares	414,207
Weighted average exercise price	$ 1.18
$1.60 - 3.20 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise price, lower range	1.60
Exercise price, upper range	$ 3.20
Number outstanding \| shares	5,720,080
Weighted average remaining contractual life (Years)	6 years 4 months 17 days
Weighted average exercise price	$ 2.54
Number vested \| shares	3,680,040
Weighted average exercise price	$ 2.54
$3.20 - 4.80 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise price, lower range	3.20
Exercise price, upper range	$ 4.80
Number outstanding \| shares	3,110,896
Weighted average remaining contractual life (Years)	3 years 10 months 17 days
Weighted average exercise price	$ 4.02
Number vested \| shares	2,858,193
Weighted average exercise price	$ 4.02
$4.80 - 6.40 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise price, lower range	4.80
Exercise price, upper range	$ 6.40
Number outstanding \| shares	5,935,013
Weighted average remaining contractual life (Years)	6 years 1 month 13 days
Weighted average exercise price	$ 5.46
Number vested \| shares	4,895,635
Weighted average exercise price	$ 5.46
$6.40 - 8.00 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise price, lower range	6.40
Exercise price, upper range	$ 8.00
Number outstanding \| shares	2,554,434
Weighted average remaining contractual life (Years)	5 years 2 months 9 days
Weighted average exercise price	$ 7.21
Number vested \| shares	2,525,441
Weighted average exercise price	$ 7.21
$8.00 - 9.60 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise price, lower range	8.00
Exercise price, upper range	$ 9.60
Number outstanding \| shares	3,061,742
Weighted average remaining contractual life (Years)	4 years 7 months 17 days
Weighted average exercise price	$ 8.77
Number vested \| shares	2,938,483
Weighted average exercise price	$ 8.77
$9.60 - 11.20 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise price, lower range	9.60
Exercise price, upper range	$ 11.20
Number outstanding \| shares	1,224,700
Weighted average remaining contractual life (Years)	4 years 11 months 9 days
Weighted average exercise price	$ 10.20
Number vested \| shares	1,224,700
Weighted average exercise price	$ 10.20
$11.20 - 12.80 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise price, lower range	11.20
Exercise price, upper range	$ 12.80
Number outstanding \| shares	423,252
Weighted average remaining contractual life (Years)	1 year 29 days
Weighted average exercise price	$ 12.10
Number vested \| shares	423,252
Weighted average exercise price	$ 12.10
$12.80 - 14.40 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise price, lower range	12.80
Exercise price, upper range	$ 14.40
Number outstanding \| shares	163,250
Weighted average remaining contractual life (Years)	1 year
Weighted average exercise price	$ 13.71
Number vested \| shares	163,210
Weighted average exercise price	$ 13.71
$14.40 - 16.00 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise price, lower range	14.40
Exercise price, upper range	$ 16.00
Number outstanding \| shares	89,000
Weighted average remaining contractual life (Years)	9 months 18 days
Weighted average exercise price	$ 15.99
Number vested \| shares	89,000
Weighted average exercise price	$ 15.99

Notes Payable (Tables)

12 Months Ended

Dec. 31, 2019

Notes Payable [Abstract]

Schedule of Payments due under Notes Payabe


	Amount
Years ending December 31,	(in thousands)
2020	$	16,491
Total remaining payments		16,491
Less: interest and discounts		(620)
Notes payable	$	15,871

Commitments and Contingencies (Narrative) (Details)		1 Months Ended	12 Months Ended
Commitments and Contingencies (Narrative) (Details)	Jul. 22, 2015 USD ($)	May 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	May 01, 2019 USD ($)	Jan. 31, 2019 USD ($)	Jan. 01, 2019 USD ($) ft²	Oct. 31, 2015 USD ($)
Commitments and Contingencies [Line Items]
Operating lease right-of-use assets, net			$ 32,827,000					$ 35,500,000
Rent payments			7,000,000
Operating lease cost			6,200,000
Long-term restricted cash			4,000,000	$ 4,500,000		$ 4,000,000			$ 4,500,000
Rent expense			6,200,000	$ 6,200,000	$ 6,300,000
Other purchase commitments			15,500,000
Additional liability associated with indemnification obligations			$ 0
1305 O’Brien Drive, Menlo Park, California [Member]
Commitments and Contingencies [Line Items]
Net rentable area \| ft²								180,000
Operating lease right-of-use assets, net							$ 35,500,000	$ 35,300,000
Renewal term			5 years
Weighted average remaining lease term			7 years 9 months 18 days
Weighted average discount rate			7.90%
Singapore and Engineering Support Facilities in Allen, Texas [Member]
Commitments and Contingencies [Line Items]
Operating lease right-of-use assets, net								$ 200,000
O’Brien Lease Agreement [Member]
Commitments and Contingencies [Line Items]
Lease term	132 months
Rent expense first twelve months	$ 540,000
Rent expense last twelve months	$ 711,000
Period in which payment must be received without incurring late charge	5 days
Late charge, percent	5.00%
Amount not paid after written notice, bear interest from date due until date paid, period	10 days
Long-term restricted cash						$ 4,000,000			$ 4,500,000
O’Brien Lease Agreement [Member] \| Prime Rate [Member]
Commitments and Contingencies [Line Items]
Basis spread on variable rate	2.00%
Forecast [Member]
Commitments and Contingencies [Line Items]
Long-term restricted cash		$ 3,500,000
Decrease in Long-term restricted cash		$ 500,000

Balance Sheet Components (Tables)

12 Months Ended

Dec. 31, 2019

Balance Sheet Components [Abstract]

Components of Inventory



	December 31,
(in thousands)	2019		2018
Purchased materials	$	3,966	$	6,222
Work in process		4,594		7,341
Finished goods		4,752		4,315
Inventory	$	13,312	$	17,878

Components of Property and Equipment, Net



	December 31,
(in thousands)	2019		2018
Laboratory equipment and machinery	$	25,173	$	24,111
Leasehold improvements		29,902		29,821
Computer equipment		11,851		9,484
Software		4,747		4,734
Furniture and fixtures		2,422		2,422
Construction in progress		193		608
		74,288		71,180
Less: Accumulated depreciation		(44,218)		(37,107)
Property and equipment, net	$	30,070	$	34,073

Schedule of Accrued Expenses



	December 31,
(in thousands)	2019		2018
Salaries and benefits	$	9,748	$	8,523
Accrued product development costs		67		561
Accrued Tenant Improvements for Menlo Park building		998		694
Inventory accrual		229		499
Accrued professional services and legal fees		943		1,588
Other		1,257		958
Accrued expenses	$	13,242	$	12,823

Income Taxes (Reconciliation of Unrecognized Tax Benefit Accounts) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Taxes [Abstract]
Unrecognized tax benefit, Beginning balance	$ 20,447	$ 18,786	$ 16,785
Decrease in balance related to tax positions taken in prior year
Increase in balance related to tax positions taken during current year	1,532	1,661	2,001
Unrecognized tax benefit, Ending balance	$ 21,979	$ 20,447	$ 18,786

Stockholders' Equity (Summary of Performance-Based RSUs Activity) (Details) - Performance-Based Restricted Stock Units (RSUs) [Member] shares in Thousands	12 Months Ended
	Dec. 31, 2019 $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares, outstanding at December 31, 2018 \| shares	586
Number of shares, granted \| shares
Number of shares, vested \| shares	(204)
Number of shares, forfeited \| shares	(244)
Number of shares, Unvested outstanding at December 31, 2019 \| shares	138
Weighted average grant date fair value, outstanding at December 31, 2018 \| $ / shares	$ 2.58
Weighted average grant date fair value, granted \| $ / shares
Weighted average grant date fair value, vested \| $ / shares	2.57
Weighted average grant date fair value, forfeited \| $ / shares	2.57
Weighted average grant date fair value, Unvested outstanding at December 31, 2019 \| $ / shares	$ 2.63

Stockholders' Equity (Schedule of Stock-Based Compensation Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 16,401	$ 23,153	$ 20,352
Cost of revenue [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	1,857	3,124	2,311
Research and development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	7,699	10,076	8,506
Sales, general and administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 6,845	$ 9,953	$ 9,535

Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Taxes [Line Items]
Income before taxes from U.S. operations	$ (84,800)	$ (103,100)	$ (92,700)
Income before taxes from foreign operations	$ 900	$ 800	$ 1,000
Statutory tax rate	21.00%	21.00%	35.00%
Valuation allowance	$ 298,658	$ 275,540
Net operating loss carryforwards	226,900
Research and development credit carryforward	45,900
Total unrecognized tax benefit	21,979	20,447	$ 18,786	$ 16,785
Accrued interest or penalties	0	$ 0
Federal [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	$ 889,600
Net operating loss carryforward, expiration	2024
Research and development credit carryforward	$ 36,400
Research and developmen tax credit carryforward, expiration	2024
State [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	$ 609,400
Net operating loss carryforward, expiration	2025
Research and development credit carryforward	$ 36,800

Segment And Geographic Information (Summary of Revenue by Category) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 27,930	$ 21,915	$ 24,621	$ 16,425	$ 19,526	$ 18,160	$ 21,578	$ 19,362	$ 90,891	$ 78,626	$ 93,468
Product [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue									77,742	66,355	80,030
Instrument [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue									45,126	28,492	38,626
Consumable [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue									32,616	37,863	41,404
Service and Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue									13,149	12,271	13,438
North America [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue									44,681	35,598	40,641
Europe (including the Middle East and Africa) [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue									19,600	13,958	14,026
Asia Pacific [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue									$ 26,610	$ 29,070	$ 38,801

Unaudited Selected Quarterly Financial Data

12 Months Ended

Dec. 31, 2019

Unaudited Selected Quarterly Financial Data [Abstract]

Unaudited Selected Quarterly Financial Data

NOTE 12. UNAUDITED SELECTED QUARTERLY FINANCIAL DATA

The following tables summarize the unaudited quarterly financial data for the last two fiscal years:



	Fiscal 2019 Quarter Ended
(in thousands, except per share data)	March 31,		June 30,		September 30,		December 31,
Total revenue	$	16,425	$	24,621	$	21,915	$	27,930
Total gross profit		5,117		9,613		6,914		12,932
Total operating expenses		35,251		33,993		35,028		30,849
Loss from operations		(30,134)		(24,380)		(28,114)		(17,917)
Gain from Continuation Advances (1)		—		—		—		18,000
Net loss		(30,324)		(24,596)		(29,123)		(91)
Basic and diluted net loss per share	$	(0.20)	$	(0.16)	$	(0.19)	$	(0.0)
Weighted average shares used in computing net loss per share		151,274		152,776		152,983		153,051

	Fiscal 2018 Quarter Ended
(in thousands, except per share data)	March 31,		June 30,		September 30,		December 31,
Total revenue	$	19,362	$	21,578	$	18,160	$	19,526
Total gross profit		7,296		8,862		3,192		5,746
Total operating expenses		31,245		30,607		27,862		36,369
Loss from operations		(23,949)		(21,745)		(24,670)		(30,623)
Net loss		(24,179)		(22,540)		(25,044)		(30,799)
Basic and diluted net loss per share	$	(0.20)	$	(0.17)	$	(0.19)	$	(0.21)
Weighted average shares used in computing net loss per share		123,768		131,882		135,130		149,314

(1) In accordance with the terms of the Merger Agreement, during the fourth quarter of 2019 we received Continuation Advances totaling $18.0 million from Illumina. Please see “Note 2 Termination of Merger with Illumina” for additional information.

Income Taxes (Reconciliation of Federal Income Tax Rate) (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Taxes [Abstract]
Statutory tax rate	21.00%	21.00%	35.00%
State tax rate, net of federal benefit	4.90%	3.50%	8.60%
Stock-based compensation	(0.80%)	(1.60%)	(1.90%)
Tax credits	2.20%	2.00%	3.60%
Remeasurement of deferred taxes due to tax reform			(123.30%)
Other	0.20%	(0.10%)	0.30%
Change in valuation allowance	(27.50%)	(24.80%)	77.70%
Total

Commitments and Contingencies

12 Months Ended

Dec. 31, 2019

Commitments and Contingencies [Abstract]

Commitments and Contingencies

NOTE 7. COMMITMENTS AND CONTINGENCIES

Lease

As of January 1, 2019, we leased approximately 180,000 square feet in 1305 O’Brien Drive, Menlo Park, California, where we house our headquarters, research and development, service and support functions, and our in-house manufacturing operations for which the right of use assets totaled $35.3 million. We also leased a sales office facility in Singapore and engineering support facilities in Allen, Texas for which the right of use assets totaled $0.2 million as of January 1, 2019.

On July 22, 2015, we entered into a lease agreement with respect to our facility located at 1305 O’Brien Drive, Menlo Park, California. The term of the O’Brien Lease is one hundred thirty-two (132) months. In December 2016, we entered into an amendment to the O’Brien Lease which defined the commencement date of the lease to be October 25, 2016, notwithstanding that such substantial completion did not occur until the first quarter of 2017. Base monthly rent was abated for the first six (6) months of the lease term and thereafter was $540,000 per month during the first year of the lease term, with specified annual increases thereafter until reaching $711,000 per month during the last twelve (12) months of the lease term. If the rent is not received within five days of the due date there will be an additional sum equal to 5% of the amount overdue as a late charge. Any amount not paid within 10 days after receipt of landlord’s written notice will bear interest from the date due until paid, at the lesser rate of (1) the prime rate of interest as published in the Wall Street Journal, plus 2% or (2) the maximum rate allowed by law, in addition to the late payment charge. We were required to establish a letter of credit for the benefits of the landlord and to submit $4.5 million as a deposit for the letter of credit in October 2015. Subsequently pursuant to the terms of the O’Brien Lease, at May 1, 2019, the $4.5 million in restricted cash was reduced to $4.0 million. As such, $4.0 million and $4.5 million was recorded in “Long-term restricted cash” in the consolidated balance sheet as of December 31, 2019 and 2018, respectively. Pursuant to the terms of the O’Brien Lease, the letter of credit balance of $4.0 million at December 31, 2019 will be reduced again in May 2020 by $500,000.

All of our leases are operating leases. Operating lease assets and liabilities are reflected within “Operating lease right-of-use assets, net”, “Operating lease liabilities, current” and “Operating lease liabilities, non-current” on the consolidated balance sheets. These assets and liabilities are recognized at the commencement date based on the present value of remaining minimum lease payments over the lease term using our estimated secured incremental borrowing rates at the effective date of January 1, 2019. Lease payments included in the measurement of the lease liability comprise the base rent per the term of the Lease. Lease expense for these leases is recognized on a straight-line basis over the lease term, with variable lease payments, such as common area maintenance fees, recognized in the period those payments are incurred.

We often have options to renew lease terms for buildings. For the O’Brien Lease, the renewal option is 5 years and the rent will be based on fair market value at the time of renewal and was not included in the lease term. In addition, certain lease arrangements may be terminated prior to their original expiration date at our discretion. We evaluate renewal and termination options at the lease commencement date to determine if we are reasonably certain to exercise the option on the basis of economic factors. The weighted average remaining lease term for our operating leases as of December 31, 2019 was 7.8 years.

The discount rate implicit within our leases is generally not determinable and therefore we determine the discount rate based on our incremental borrowing rate. The incremental borrowing rate for our leases is determined based on lease term and currency in which lease payments are made, adjusted for impacts of collateral. The weighted average discount rate used to measure our operating lease liabilities as of December 31, 2019 was 7.9%.

The following table presents information as to the amount and timing of cash flows arising from our operating leases as of December 31, 2019:



Maturity of Lease Liabilities	Amount
Years ending December 31,	(in thousands)
2020	$	7,150
2021		7,306
2022		7,488
2023		7,704
2024		7,920
Thereafter		23,598
Total undiscounted operating lease payments		61,166
Less: imputed interest		(15,365)
Present value of operating lease liabilities	$	45,801

Balance Sheet Classification
Operating lease liabilities, current	$	3,837
Operating lease liabilities, non-current		41,964
Total operating lease liabilities	$	45,801

Cash Flows

An initial right-of-use asset of $35.5 million was recognized on the consolidated balance sheet as of January 1, 2019 with the adoption of the new lease accounting standard. Cash paid for amounts included in the present value of operating lease liabilities was $7.0 million for the year ended December 31, 2019 and included in operating cash flow.

Operating Lease Costs

Operating lease costs were $6.2 million for the year ended December 31, 2019, primarily related to our operating leases, but also include immaterial amounts for variable lease payments.

Rent expense for the years ended December 31, 2019, 2018 and 2017 was $6.2 million, $6.2 million and $6.3 million, respectively. We are also required to pay our share of operating expenses with respect to the facilities in which we operate.

Contingencies

We may become involved in legal proceedings, claims and assessments from time to time in the ordinary course of business. We accrue liabilities for such matters when it is probable that future expenditures will be made and such expenditures can be reasonably estimated.

In addition, we had other purchase commitments of an estimated amount of approximately $15.5 million as of December 31, 2019, consisting of open purchase orders and contractual obligations in the ordinary course of business, including commitments with contract manufacturers and suppliers for which we have not received the goods or services, and acquisition and licensing of intellectual property. A majority of these purchase obligations are due within a year. Although open purchase orders are considered enforceable and legally binding, the terms generally allow us the option to cancel, reschedule and adjust our requirements based on our business needs prior to the delivery of goods or performance of services.

Legal Proceedings

USITC Proceedings

On November 2, 2016, we filed a complaint against Oxford Nanopore Technologies Ltd. (“ONT Ltd.”), Oxford Nanopore Technologies, Inc. (“ONT Inc.”) and Metrichor, Ltd. (“Metrichor” and, together with ONT Ltd. and ONT Inc., “ONT”) with the U.S. International Trade Commission (“USITC”) for patent infringement. On December 5, 2016, the USITC provided notice that an investigation had been instituted based on the complaint. We sought exclusionary relief with respect to several ONT products, including ONT’s MinION and PromethION devices. The complaint was based on our U.S. Patent No. 9,404,146, entitled “Compositions and methods for nucleic acid sequencing” which covers novel methods for sequencing single nucleic acid molecules using linked double-stranded nucleic acid templates, providing improved sequencing accuracy. On March 1, 2017, we filed an amended complaint to add a second patent in the same patent family, U.S. Patent No. 9,542,527, which was granted on January 10, 2017, to the investigation. We sought, among other things, an exclusion order permanently barring entry of infringing ONT products into the United States, and a cease and desist order preventing ONT from advertising and selling infringing products in the United States. On May 23, 2017, the Administrative Law Judge (“ALJ”) assigned to the matter issued an order construing certain claim terms of the asserted patents. On June 8, 2017, ONT filed a summary determination motion to terminate the proceedings based on the ALJ’s claim construction decision, and we did not oppose the motion. The ALJ granted the motion on July 19, 2017, and, on July 31, 2017, we filed a petition to review with the USITC to correct what we believe was an incorrect construction of the claims. On September 5, 2017, the USITC issued a notice granting our petition to review the ALJ’s claim construction decision. On February 7, 2018, the USITC issued a notice indicating that it had determined to adopt the ALJ’s claim construction and terminating the investigation. On February 13, 2018, we filed a petition to appeal the USITC’s ruling to the U.S. Court of Appeals for the Federal Circuit. (“Federal Circuit”). An oral hearing for this appeal was held on February 8, 2019. On February 12, 2019, the Federal Circuit filed a judgement affirming the USITC claim construction under Federal Circuit Rule 36 without a written opinion.

U.S. District Court Proceedings

On March 15, 2017, we filed a complaint in the U.S. District Court for the District of Delaware against ONT Inc. for patent infringement (C.A. No. 17-cv-275 (“275 Action”)). The complaint is based on our U.S. Patent No. 9,546,400 (the “’400 Patent”), entitled “Nanopore sequencing using n-mers” which covers novel methods for nanopore sequencing of nucleic acid molecules using the signals from multiple monomeric units. This patent was granted on January 17, 2017. We are seeking remedies including injunctive relief, damages and costs. On August 23, 2018, we filed an amended complaint, adding ONT Ltd. as a defendant in the 275 Action. On August 15, 2019, the judge granted our motion to amend the complaint in the 275 Action to add allegations of willful infringement by ONT Inc. and ONT Ltd.

On September 25, 2017, we filed a second complaint in the U.S. District Court for the District of Delaware against ONT Inc. for patent infringement (C.A. No. 17-cv-1353 (“1353 Action”)). The complaint is based on our U.S. Patent No. 9,678,056 (the “’056 Patent”) entitled “Control of Enzyme Translation in Nanopore Sequencing”, granted June 13, 2017, and U.S. Patent No. 9,738,929 (the “’929 Patent”) entitled “Nucleic Acid Sequence Analysis”, granted August 22, 2017. We are seeking remedies including injunctive relief, damages and costs. On March 28, 2018, we added a claim for infringement of our U.S. Patent No. 9,772,323 (the “’323 Patent”), entitled “Nanopore sequencing using n-mers.” On August 23, 2018 we filed an amended complaint, adding ONT Ltd. as a defendant in the 1353 Action. On August 15, 2019, the judge granted our motion to amend the complaint in the 1353 Action to add allegations of willful infringement by ONT Inc. and ONT Ltd.

A claim construction (or “Markman”) hearing for the U.S. District Court matters was held on December 17, 2018. On March 6, 2019, a claim construction order construing various claim terms in the patents in suit was issued. On January 8, 2020, the Court held a summary judgement and expert testimony admissibility (or “Daubert”) hearing. On February 19, 2020, the Court issued its summary judgement and Daubert opinions. All of our claims survived summary judgement. A trial for the U.S. District Court matters is scheduled to begin on March 9, 2020.

Unrelated to the preceding matters, on September 26, 2019, Personal Genomics of Taiwan, Inc. (“PGI”) filed a complaint in the U.S. District Court for the District of Delaware against us for patent infringement (C.A. No. 19-cv-1810). The complaint is based on PGI’s U.S. Patent No. 7,767,441. We plan to vigorously defend in this matter. On November 20, 2019, we filed our answer to the complaint, denying infringement and seeking a declaratory judgement of invalidity of the ‘441 Patent. A trial for this matter is scheduled to begin on March 14, 2022.

UK and German Court Proceedings

On February 2, 2017, we filed a claim in the High Court of England and Wales against ONT Ltd. and Metrichor for infringement of Patent EP(UK) 3 045 542 (the “’542 Patent”), which is in the same patent family as the patents asserted in the USITC action referred to above. We sought remedies including injunctive relief, damages, and costs. On August 31, 2017, we added a claim for infringement of a newly granted divisional, EP(UK) 3 170 904 (the “’904 Patent”). On December 22, 2017, ONT Ltd. added to the action a request for declaration of non-infringement of its 1D2 product. A trial for these matters was scheduled to occur in May 2018.

On April 21, 2017, ONT Ltd. and Harvard University filed a claim against us in the High Court of England and Wales for infringement of Patent EP(UK) 1 192 453 (the “’453 Patent”), a patent owned by Harvard University and entitled “Molecular and atomic scale evaluation of biopolymers,” and for which ONT Ltd. alleges it holds an exclusive license. ONT Ltd. and Harvard University sought remedies including injunctive relief, damages, and costs. On April 25, 2017, ONT Ltd. announced that it also had filed a claim against us in the District Court of Mannheim, Germany, for infringement of the German version of the patent. On December 6, 2017, we filed a cross-complaint in the German infringement matter alleging ONT Ltd.’s infringement in Germany of our ’542 Patent. The trial date for the German infringement matter and cross-complaint was set for July 27, 2018. A trial for the UK matter was scheduled to occur in March 2019.

On May 8, 2018, the parties entered a settlement of all UK and German court proceedings pending as of such date. Under the terms of the settlement, ONT agreed not to make, dispose of, use or import any “2D” nanopore sequencing products, or to induce or assist others to carry out a “2D” sequencing process, in the UK or Germany, through the end of 2023. During this time, we agreed not to assert the ’542 Patent and ’904 Patent against either ONT or its customers in the UK or Germany. Accordingly, the High Court of England and Wales entered an order staying our UK action against ONT through the end of 2023. As part of the settlement, ONT and Harvard University dismissed their UK and German actions under the ’453 Patent and agreed not to assert the ’453 Patent against us or our customers through the end of 2023. We correspondingly agreed to dismiss our separate German nullity action seeking to invalidate the ’453 Patent, which expires on June 22, 2020.

Related to these proceedings, on August 15, 2017, ONT Ltd. filed a notice of opposition to our ’542 Patent with the European Patent Office, and on August 16, 2017, an anonymous party filed a second notice of opposition to the same patent, each alleging invalidity of the patent. On April 5, 2018, we filed our response to the combined opposition. On January 22, 2019, an oral hearing in the matter occurred and the European Patent Office rendered a decision in favor of the opponents. We believe the European Patent Office errored in its decision and we are appealing the decision. The ’542 Patent will remain in effect while the appeal is pending. Our settlement agreement with ONT Ltd. and Harvard University will also remain in effect regardless of the outcome of the appeal.

Also related to these proceedings, on May 16, 2018, ONT Ltd. filed a notice of opposition to our ’904 Patent with the European Patent Office alleging invalidity of the ’904 Patent. On October 11, 2018, we filed our response to the opposition. On July 16, 2019, an oral hearing in the matter occurred and the European Patent Office rendered a decision in favor of the opponents. We believe the European Patent Office erred in its decision and we are appealing the decision. The ’904 Patent will remain in effect while the appeal is pending. Our settlement agreement with ONT Ltd. and Harvard University will also remain in effect regardless of the outcome of the appeal.

Litigation is inherently unpredictable, and, except for events that have already occurred, it is too early in the foregoing proceedings, including the U.S. District Court Proceedings, to predict the outcome of these proceedings, or any impact they may have on us. As such, the estimated financial effect associated with these complaints cannot be made as of the date of filing of this Annual Report on Form 10-K. Litigation is a significant ongoing expense with an uncertain outcome, and has been in the past and may in the future be a material expense for us. Management believes this investment is important to protect our intellectual property position, even recognizing the uncertainty of the outcome.

Other Proceedings

From time to time, we may also be involved in a variety of other claims, lawsuits, investigations and proceedings relating to securities laws, product liability, patent infringement, contract disputes, employment and other matters that arise in the normal course of our business. In addition, third parties may, from time to time, assert claims against us in the form of letters and other communications. We record a provision for contingent losses when it is both probable that a liability has been incurred and the amount of the loss can be reasonably estimated. We currently do not believe that the ultimate outcome of any of the matters described above is probable or reasonably estimable, or that these matters will have a material adverse effect on our business; however, the results of litigation and claims are inherently unpredictable. Regardless of the outcome, litigation can have an adverse impact on us because of litigation and settlement costs, diversion of management resources and other factors.

Indemnification

Pursuant to Delaware law and agreements entered into with each of our directors and officers, we may have obligations, under certain circumstances, to hold harmless and indemnify each of our directors and officers against losses suffered or incurred by the indemnified party in connection with their service to us, and judgements, fines, settlements and expenses related to claims arising against such directors and officers to the fullest extent permitted under Delaware law, our bylaws and certificate of incorporation. We also enter and have entered into indemnification agreements with our directors and officers that may require us to indemnify them against liabilities that arise by reason of their status or service as directors or officers, except as prohibited by applicable law. In addition, we may have obligations to hold harmless and indemnify third parties involved with our fund raising efforts and their respective affiliates, directors, officers, employees, agents or other representatives against any and all losses, claims, damages and liabilities related to claims arising against such parties pursuant to the terms of agreements entered into between such third parties and us in connection with such fund raising efforts. To the extent that any such indemnification obligations apply to the lawsuits described above, any associated expenses incurred are included within the related accrued litigation expense amounts. No additional liability associated with such indemnification obligations has been recorded at December 31, 2019.

Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2019

Summary of Significant Accounting Policies [Abstract]

Summary of Assets and Liabilities Measured at Fair Value on a Recurring Basis



	December 31, 2019								December 31, 2018
(in thousands)	Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
Assets
Cash and cash equivalents:
Cash and money market funds	$	18,644	$	—	$	—	$	18,644	$	18,844	$	—	$	—	$	18,844
Commercial paper		—		10,983		—		10,983		—		—		—		—
Total cash and cash equivalents		18,644		10,983		—		29,627		18,844		—		—		18,844
Investments:
Commercial paper		—		16,971		—		16,971		—		53,469		—		53,469
Corporate debt securities		—		2,501		—		2,501		—		10,214		—		10,214
US government & agency securities		—		—		—		—		—		19,827		—		19,827
Total investments		—		19,472		—		19,472		—		83,510		—		83,510
Long-term restricted cash:
Cash		4,000		—		—		4,000		4,500		—		—		4,500
Total assets measured at fair value	$	22,644	$	30,455	$	—	$	53,099	$	23,344	$	83,510	$	—	$	106,854

Liabilities
Financing derivative	$	—	$	—	$	—	$	—	$	—	$	—	$	16	$	16
Continuation Advances		—		—		—		—		—		—		—		—
Total liabilities measured at fair value	$	—	$	—	$	—	$	—	$	—	$	—	$	16	$	16

Changes in Fair Value of Financing Derivative



Financing Derivative	Amount
Balance as of December 31, 2017	$	183
Gain on change in fair value of Financing Derivative		(167)
Balance as of December 31, 2018		16
Gain on change in fair value of Financing Derivative		(16)
Balance as of December 31, 2019	$	—

Estimated Fair Value and Carrying Value of Notes



	December 31, 2019				December 31, 2018
	Fair Value		Carrying Value		Fair Value		Carrying Value
Long-term notes payable	$	16,038	$	15,871	$	15,915	$	14,659

- Definition

Tabular disclosure of financial instruments measured at fair value, including those classified in shareholders' equity measured on a recurring or nonrecurring basis. Disclosures include, but are not limited to, fair value measurements recorded and the reasons for the measurements, level within the fair value hierarchy in which the fair value measurements are categorized and transfers between levels 1 and 2. Nonrecurring fair value measurements are those that are required or permitted in the statement of financial position in particular circumstances.

+ References + Details

Income Taxes

12 Months Ended

Dec. 31, 2019

Income Taxes [Abstract]

Income Taxes

NOTE 8. INCOME TAXES

We are subject to income taxes in the United States and certain states in which we operate, and we use estimates in determining our provisions for income taxes. Significant management judgement is required in determining our provision for income taxes, deferred tax assets and liabilities and valuation allowances recorded against net deferred tax assets in accordance with U.S. GAAP. These estimates and judgements occur in the calculation of tax credits, benefits, and deductions, and in the calculation of certain tax assets and liabilities, which arise from differences in the timing of recognition of revenue and expense for tax and financial statement purposes, as well as the interest and penalties related to uncertain tax positions. Significant changes to these estimates may result in an increase or decrease to our tax provision in the current or subsequent period.

We assess all material positions taken in any income tax return, including all significant uncertain positions, in all tax years that are still subject to assessment or challenge by relevant taxing authorities. Assessing an uncertain tax position begins with the initial determination of the position’s sustainability and is measured at the largest amount of benefit that is greater than 50% likely of being realized upon ultimate settlement. As of each balance sheet date, unresolved uncertain tax positions must be reassessed, and we will determine whether the factors underlying the sustainability assertion have changed and the amount of the recognized tax benefit is still appropriate.

During the years ended December 31, 2019, 2018 and 2017 income before taxes from U.S. operations were ($84.8) million, ($103.1) million and ($92.7) million, respectively, and income before taxes from foreign operations was $0.9 million, $0.8 million and $1.0 million, respectively.

Income tax provision (benefit) related to continuing operations differ from the amounts computed by applying the statutory income tax rate of 21% to pretax loss as follows (in thousands):



	Years ended December 31,
	2019		2018		2017
Statutory tax rate	21.0	%	21.0	%	35.0	%
State tax rate, net of federal benefit	4.9		3.5		8.6
Stock-based compensation	(0.8)		(1.6)		(1.9)
Tax credits	2.2		2.0		3.6
Remeasurement of deferred taxes due to tax reform	-		-		(123.3)
Other	0.2		(0.1)		0.3
Change in valuation allowance	(27.5)		(24.8)		77.7
Total	-	%	-	%	-	%

Deferred income taxes reflect the net tax effects of loss and credit carry forwards and temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Significant components of our deferred tax assets for federal and state income taxes are as follows (in thousands):



	December 31,
Deferred tax assets:	2019		2018
Net operating loss carryforwards	$	226,911	$	212,424
Research and development credits		45,853		42,635
Accruals and reserves		8,024		4,774
Stock-based compensation		16,219		14,582
Deferred rent		—		3,315
ASC842 Operating lease liability		10,837		—
Total deferred tax assets		307,844		277,730
Less: Valuation allowance		(298,658)		(275,540)
Total deferred tax assets:		9,186		2,190
Fixed assets		(1,425)		(2,190)
ASC842 Operating lease right-of-use assets		(7,761)		—
Total deferred tax liabilities		(9,186)		(2,190)
Net deferred tax assets	$	—	$	—

At December 31, 2019, we maintained a full valuation allowance against all of our deferred tax assets which totaled $298.7 million, including net operating loss carryforwards and research and development credits of $226.9 million and $45.9 million, respectively.

Due to uncertainties surrounding the realization of deferred tax assets through future taxable income, we have provided a full valuation allowance and, therefore, have not recognized any benefits from net operating losses and other deferred tax assets.

A valuation allowance is recorded when it is more likely than not that all or some portion of the deferred income tax assets will not be realized. We regularly assess the need for a valuation allowance against our deferred income tax assets by considering both positive and negative evidence related to whether it is more likely than not that our deferred income tax assets will be realized. In evaluating our ability to recover our deferred income tax assets within the jurisdiction from which they arise, we consider all available positive and negative evidence, including scheduled reversals of deferred income tax liabilities, projected future taxable income, tax-planning strategies, and results of recent operations. Accordingly, we have provided a full valuation allowance against our net deferred tax assets as of December 31, 2019 and 2018, respectively.

For the year ended December 31, 2019 and 2018, our valuation allowance increased to $298.7 million and 275.5 million, respectively, primarily because of an increase to our net operating losses, and credits and changes in book to tax timing differences.

As of December 31, 2019, we had a net operating loss carryforward for federal income tax purposes of approximately $889.6 million, portion of which will begin to expire in 2024. We had a total state net operating loss carryforward of approximately $609.4 million, which have expiration dates of 2025 and beyond. Utilization of some of the federal and state net operating loss and credit carryforwards are subject to annual limitations due to the “change of ownership” provisions of the Internal Revenue Code of 1986 and similar state provisions. The annual limitations may result in the expiration of net operating losses and credits before utilization.

We have federal credits of approximately $36.4 million, which will begin to expire in 2024 if not utilized and state research credits of approximately $36.8 million which have no expiration date. These tax credits are subject to the same limitations discussed above.

As of December 31, 2019, our total unrecognized tax benefit was $22.0 million.

A reconciliation of the beginning and ending unrecognized tax benefit balance is as follows (in thousands):



Balance as of December 31, 2016	$	16,785
Decrease in balance related to tax positions taken in prior year		—
Increase in balance related to tax positions taken during current year		2,001
Balance as of December 31, 2017		18,786
Decrease in balance related to tax positions taken in prior year		—
Increase in balance related to tax positions taken during current year		1,661
Balance as of December 31, 2018	$	20,447
Decrease in balance related to tax positions taken in prior year		—
Increase in balance related to tax positions taken during current year		1,532
Balance as of December 31, 2019	$	21,979

Our practice is to recognize interest and/or penalties related to income tax matters in income tax expense. As of December 31, 2019 and 2018, we had no accrued interest or penalties due to our net operating losses available to offset any tax adjustment. If total unrecognized tax benefits were realized in the future, it would not result in any tax benefit as we currently have a full valuation allowance. We file U.S. federal and various state income tax returns. For U.S. federal and state income tax purposes, the statute of limitations currently remains open for the years ending December 31, 2016 to present and December 31, 2015 to present, respectively. In addition, all of the net operating losses and research and development credit carryforwards that may be utilized in future years may be subject to examination. We are not currently under examination by income tax authorities in any jurisdiction.

On December 22, 2017, the 2017 Tax Cuts and Jobs Act (Tax Act) was enacted into law and the new legislation contains several key tax provisions that affected us, including a one-time mandatory transition tax on accumulated foreign earnings and a reduction of the corporate income tax rate to 21% effective January 1, 2018, among others. We are required to recognize the effect of the tax law changes in the period of enactment, such as determining the transition tax, remeasuring our U.S. deferred tax assets and liabilities as well as reassessing the net realizability of our deferred tax assets and liabilities. In December 2017, the SEC staff issued Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act (SAB 118), which allowed us to record provisional amounts during a measurement period not to extend beyond one year of the enactment date. As a result, we previously provided a provisional estimate of the effect of the Tax Act in our financial statements. In the fourth quarter of 2018, we completed our analysis to determine the effect of the Tax Act and recorded immaterial adjustments as of December 31, 2018.

Stockholders' Equity (Summary of Time-Based RSUs Activity) (Details) - Time-Based Restricted Stock Units (RSUs) [Member] shares in Thousands	12 Months Ended
	Dec. 31, 2019 $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares, outstanding at December 31, 2018 \| shares	371
Number of shares, granted \| shares	900
Number of shares, vested \| shares	(127)
Number of shares, forfeited \| shares	(58)
Number of shares, Unvested outstanding at December 31, 2019 \| shares	1,086
Weighted average grant date fair value, outstanding at December 31, 2018 \| $ / shares	$ 3.20
Weighted average grant date fair value, granted \| $ / shares	7.06
Weighted average grant date fair value, vested \| $ / shares	4.35
Weighted average grant date fair value, forfeited \| $ / shares	5.86
Weighted average grant date fair value, Unvested outstanding at December 31, 2019 \| $ / shares	$ 6.12

Balance Sheet Components (Components of Inventory) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Balance Sheet Components [Abstract]
Purchased materials	$ 3,966	$ 6,222
Work in process	4,594	7,341
Finished goods	4,752	4,315
Inventory	$ 13,312	$ 17,878

Summary of Significant Accounting Policies (Changes in Fair Value of Financing Derivative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Summary of Significant Accounting Policies [Abstract]
Balance, Beginning	$ 16,000	$ 183,000
Gain on change in fair value of Financing Derivative	(16,000)	(167,000)
Balance, Ending	$ 0	$ 16,000

Balance Sheet Components (Schedule of Accrued Expenses) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Balance Sheet Components [Abstract]
Salaries and benefits	$ 9,748	$ 8,523
Accrued product development costs	67	561
Accrued Tenant Improvements for Menlo Park building	998	694
Inventory accrual	229	499
Accrued professional services and legal fees	943	1,588
Other	1,257	958
Accrued expenses	$ 13,242	$ 12,823

Document And Entity Information - USD ($) $ in Thousands	12 Months Ended
Document And Entity Information - USD ($) $ in Thousands	Dec. 31, 2019	Jan. 31, 2020	Jun. 30, 2019
Document And Entity Information [Abstract]
Document Type	10-K
Document Annual Report	true
Current Fiscal Year End Date	--12-31
Document Period End Date	Dec. 31, 2019
Document Fiscal Year Focus	2019
Document Transition Report	false
Entity File Number	001-34899
Entity Registrant Name	Pacific Biosciences of California, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	16-1590339
Entity Address, Address Line One	1305 O’Brien Drive
Entity Address, City or Town	Menlo Park
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94025
City Area Code	650
Local Phone Number	521-8000
Title of 12(b) Security	Common Stock, par value $0.001 per share
Trading Symbol	PACB
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 855,320
Entity Common Stock Shares Outstanding		153,135,470
Amendment Flag	false
Entity Central Index Key	0001299130
Document Fiscal Period Focus	FY
Documents Incorporated by Reference	Portions of the registrant’s definitive Proxy Statement relating to its 2020 Annual Meeting of Stockholders to be held on June 18, 2020 are incorporated by reference into Part III of this Annual Report on Form 10-K where indicated. Such Proxy Statement will be filed with the U.S. Securities and Exchange Commission within 120 days after the end of the fiscal year to which this report relates.

Termination of Merger with Illumina (Narrative) (Details) - USD ($) $ in Thousands			1 Months Ended			3 Months Ended	12 Months Ended
	Mar. 20, 2020	Jan. 02, 2020	Mar. 31, 2020	Feb. 29, 2020	Jan. 31, 2020	Dec. 31, 2019	Dec. 31, 2019	Mar. 02, 2020	Feb. 03, 2020	Dec. 02, 2019	Nov. 01, 2019	Oct. 01, 2019
Merger Termination [Line Items]
Continuation Advances due for merger										$ 6,000	$ 6,000	$ 6,000
Gain from Continuation Advances from Illumina						$ 18,000	$ 18,000
Continuation Advances from Illumina						$ 18,000	$ 18,000
Period in which company must repay continuation advances if change-of-controll transaction is entered into with third party							2 years
Equity or debt financing that must be raised in a single transaction							$ 100,000
Forecast [Member]
Merger Termination [Line Items]
Continuation Advances due for merger								$ 6,000
Continuation Advances from Illumina			$ 6,000	$ 22,000
Period in which company must repay continuation advances if change-of-controll transaction is entered into with third party	2 years
Equity or debt financing that must be raised in a single transaction	$ 100,000
Subsequent Event [Member]
Merger Termination [Line Items]
Continuation Advances due for merger		$ 6,000							$ 22,000
Continuation Advances from Illumina					$ 6,000
Termination fee received		98,000
Advisor fee payable		$ 10,000

Summary of Significant Accounting Policies (Policy)

12 Months Ended

Dec. 31, 2019

Summary of Significant Accounting Policies [Abstract]

Basis of Presentation and Consolidation

Our consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States, or U.S. GAAP, as set forth in the Financial Accounting Standards Board, or FASB, Accounting Standards Codification, or ASC. The consolidated financial statements include the accounts of Pacific Biosciences and our wholly owned subsidiaries. All intercompany transactions and balances have been eliminated. Translation adjustments resulting from translating foreign subsidiaries’ results of operations and assets and liabilities into U.S. dollars are immaterial for all periods presented.

Use of Estimates

The preparation of financial statements in conformity with U.S. GAAP requires us to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes to the financial statements. Our estimates include, but are not limited to, the valuation of inventory, the determination of stand-alone selling prices for revenue recognition, the valuation of a financing derivative and long-term notes, the probability of repaying the Continuation Advances to Illumina, the valuation and recognition of share-based compensation, the expected renewal period for service contracts to derive the amortization period for capitalized commissions, the useful lives assigned to long-lived assets, the computation of provisions for income taxes and the determination of the internal borrowing rate used in calculating the operating lease right-of-use assets and operating lease liabilities. Actual results could differ materially from these estimates.

During 2017, we recorded a charge to cost of service and other revenue of $1.6 million relating to leased RS II instruments primarily due to a change in the estimated useful life of these instruments. The charge of $1.6 million increased loss per share by $0.01 for the year ended December 31, 2017.

Accounting Changes

Accounting changes

In February 2016, the FASB issued ASU 2016-02 regarding ASC Topic 842 Leases and in July 2018, the FASB issued ASU 2018-11, Leases (Topic 842): Targeted Improvements. We refer to the new guidance as “ASC 842”. On January 1, 2019, we adopted the ASC 842 using a modified retrospective approach, which requires the recognition of right-of-use assets and related operating and finance lease liabilities on the consolidated balance sheet. As permitted by ASC 842, we elected the adoption date of January 1, 2019, which is the date of initial application. As a result,

the consolidated balance sheet prior to January 1, 2019 was not restated and continues to be reported under ASC Topic 840, Leases, or “ASC 840”, which did not require the recognition of right-of-use assets and operating lease liabilities on the consolidated balance sheet and;

the expense recognition for operating leases under ASC 842 remained substantially consistent with ASC 840.

Fair Value of Financial Instruments

The carrying amount of our accounts receivable, prepaid expenses, other current assets, accounts payable, accrued expenses and other liabilities, current, approximate fair value due to their short maturities.

The fair value hierarchy established under U.S. GAAP requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The three levels of inputs that may be used to measure fair value are as follows:

Level 1: quoted prices in active markets for identical assets or liabilities;

Level 2: inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices in active markets for similar assets or liabilities, quoted prices for identical or similar assets or liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities; and

Level 3: unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.

We consider an active market as one in which transactions for the asset or liability occurs with sufficient frequency and volume to provide pricing information on an ongoing basis. Conversely, we view an inactive market as one in which there are few transactions for the asset or liability, the prices are not current, or price quotations vary substantially either over time or among market makers. Where appropriate, our non-performance risk, or that of our counterparty, is considered in determining the fair values of liabilities and assets, respectively.

We classify our cash deposits and money market funds within Level 1 of the fair value hierarchy because they are valued using bank balances or quoted market prices. We classify our investments as Level 2 instruments based on market pricing and other observable inputs. We did not classify any of our investments within Level 3 of the fair value hierarchy.

Assets and liabilities measured at fair value are classified in their entirety based on the lowest level input that is significant to the fair value measurement. Our assessment of the significance of a particular input to the entire fair value measurement requires management to make judgments and consider factors specific to the asset or liability.

Assets and Liabilities Measured at Fair Value on a Recurring Basis

The following table sets forth the fair value of our financial assets and liabilities that were measured on a recurring basis as of December 31, 2019 and 2018, respectively (in thousands):



	December 31, 2019								December 31, 2018
(in thousands)	Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
Assets
Cash and cash equivalents:
Cash and money market funds	$	18,644	$	—	$	—	$	18,644	$	18,844	$	—	$	—	$	18,844
Commercial paper		—		10,983		—		10,983		—		—		—		—
Total cash and cash equivalents		18,644		10,983		—		29,627		18,844		—		—		18,844
Investments:
Commercial paper		—		16,971		—		16,971		—		53,469		—		53,469
Corporate debt securities		—		2,501		—		2,501		—		10,214		—		10,214
US government & agency securities		—		—		—		—		—		19,827		—		19,827
Total investments		—		19,472		—		19,472		—		83,510		—		83,510
Long-term restricted cash:
Cash		4,000		—		—		4,000		4,500		—		—		4,500
Total assets measured at fair value	$	22,644	$	30,455	$	—	$	53,099	$	23,344	$	83,510	$	—	$	106,854

Liabilities
Financing derivative	$	—	$	—	$	—	$	—	$	—	$	—	$	16	$	16
Continuation Advances		—		—		—		—		—		—		—		—
Total liabilities measured at fair value	$	—	$	—	$	—	$	—	$	—	$	—	$	16	$	16

Estimated fair value of the Financing Derivative liability

The estimated fair value of the Financing Derivative liability (as defined in “Note 6. Notes Payable’) was determined using Level 3 inputs, or significant unobservable inputs. Refer to “Note 6. Notes Payable” for a detailed description and valuation approach. Changes to the estimated fair value of the Financing Derivative are recorded in “Other income (expense), net” in the consolidated statements of operations and comprehensive loss.

The following table provides the changes in the fair value of the Financing Derivative for the years ended December 31, 2019 and 2018 (in thousands), respectively:



Financing Derivative	Amount
Balance as of December 31, 2017	$	183
Gain on change in fair value of Financing Derivative		(167)
Balance as of December 31, 2018		16
Gain on change in fair value of Financing Derivative		(16)
Balance as of December 31, 2019	$	—

Estimated fair value of the Continuation Advances liability

On November 1, 2018, we entered into a Merger Agreement with Illumina and FC Ops Corp. We, Illumina and Merger Subsidiary entered into the Amendment on September 25, 2019. In accordance with the terms of the Merger Agreement, we received Continuation Advances totaling $18.0 million from Illumina during the fourth quarter of 2019.

We determined that the $18.0 million of Continuation Advances received from Illumina in 2019, which are subject to repayment under certain circumstances as discussed above, constitute a financial liability.

The fair value option was elected for the financial liability because management believes that among all measurement methods allowed by ASC 825, Financial Instruments, the fair value option would most fairly represent the value of such a financial liability. Management applied the income approach to estimate the fair value of this financial liability. The estimated fair value of the liability related to the Continuation Advances received in 2019 was determined using Level 3 inputs, or significant unobservable inputs. Management estimated that there would be no future cash outflows associated with this financial instrument because the probabilities of either of the following events occurring and requiring repayment to Illumina were evaluated as being remote as of December 31, 2019:

We enter into a Change of Control Transaction (as defined in the Termination Agreement) within two years following March 31, 2020;

We raise $100 million or more in a single equity or debt financing (that may have multiple closings) within two years following March 31, 2020.

As a result, the estimated fair value of the liability associated with the contingent repayment of the $18.0 million of Continuation Advances received in the fourth quarter of 2019 was assessed to be zero as of December 31, 2019, with a resulting non-operating gain of $18.0 million recorded as “Gain from Continuation Advances from Illumina” in the consolidated statements of operations and comprehensive loss for the year ended December 31, 2019.

For the year ended December 31, 2019, there were no transfers between Level 1, Level 2, or Level 3 assets or liabilities reported at fair value on a recurring basis and our valuation techniques did not change compared to the prior year.

Financial Assets and Liabilities Not Measured at Fair Value on a Recurring Basis

We determined the fair value of the Notes (as defined in “Note 6. Notes Payable”) from the Facility Agreement we entered into during the first quarter of 2013 using Level 3 inputs, or significant unobservable inputs. The value of the Notes was determined by comparing the difference between the fair value of the Notes with and without the Financing Derivative by calculating the respective present values from future cash flows using a 6.5% and 9.6% weighted average market yield at December 31, 2019 and December 31, 2018, respectively. Refer to “Note 6. Notes Payable” for additional details regarding the Notes. The estimated fair value and carrying value of the Notes are as follows (in thousands):



	December 31, 2019				December 31, 2018
	Fair Value		Carrying Value		Fair Value		Carrying Value
Long-term notes payable	$	16,038	$	15,871	$	15,915	$	14,659

Cash And Cash Equivalents

Cash and Cash Equivalents

We consider all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents.

Investments

We have designated all investments as available-for-sale and therefore, such investments are reported at fair value, with unrealized gains and losses recognized in accumulated other comprehensive income (loss) (“OCI”) in stockholders’ equity. The cost of marketable securities is adjusted for the amortization of premiums and discounts to expected maturity. Premium and discount amortization is included in other income, net. Realized gains and losses, as well as interest income, on available-for-sale securities are also included in other income, net. The cost of securities sold is based on the specific identification method. We include all of our available-for-sale securities in current assets.

All of our investments are subject to a periodic impairment review. We recognize an impairment charge when a decline in the fair value of our investments below the cost basis is judged to be other-than-temporary. Factors considered in determining whether a loss is temporary include the length of time and the extent to which an investment’s fair value has been less than its cost basis, the financial condition and near-term prospects of the investee, the extent of the loss related to credit of the issuer, the expected cash flows from the security, our intent to sell the security and whether or not we will be required to sell the security before the recovery of its amortized cost. During the years ended December 31, 2019, 2018 and 2017, we did not have any impairment charges on our investments as it is more likely than not that we will recover their amortized cost basis upon sale or maturity.

Concentration and Other Risks

The counterparties to the agreements relating to our investment securities consist of various major corporations, financial institutions, municipalities and government agencies of high credit standing. Our accounts receivable are derived from net revenue to customers and distributors located in the United States and other countries. We perform credit evaluations of our customers’ financial condition and, generally, require no collateral from our customers. We regularly review our accounts receivable including consideration of factors such as historical experience, credit quality, the age of the accounts receivable balances and current economic conditions that may affect a customer’s ability to pay. We have not experienced any significant credit losses to date.

For the years ended December 31, 2019, 2018 and 2017, one customer, Gene Company Limited, accounted for approximately 17%, 26% and 31% of our total revenue, respectively.

As of December 31, 2019 and 2018, 55% and 50% of our accounts receivable were from domestic customers, respectively. As of December 31, 2019 and 2018, one customer, Gene Company Limited, represented approximately 11% and 14% of our net accounts receivable, respectively. We currently purchase several key parts and components used in the manufacture of our products from a limited number of suppliers. Generally, we have been able to obtain an adequate supply of such parts and components. However, an extended interruption in the supply of parts and components currently obtained from our suppliers could adversely affect our business and consolidated financial statements.

Inventory

Inventories are stated at the lower of average cost or net realizable value. Cost is determined using the first-in, first-out (“FIFO”) method. Adjustments to reduce the cost of inventory to its net realizable value, if required, are made for estimated excess or obsolete balances.

Property And Equipment, Net

Property and Equipment, Net

Property and equipment are stated at cost, net of accumulated depreciation and any impairment charges. Depreciation is computed using the straight-line method over the estimated useful life of the asset, generally two to three years for computer equipment, three to five years for software, three to seven years for furniture and fixtures and three to five years for lab equipment. Leasehold improvements are depreciated over the shorter of the lease term or the estimated useful life of the related asset. Major improvements are capitalized, while maintenance and repairs are expensed as incurred.

Long-Term Restricted Cash

Long-term Restricted Cash

As required under the lease agreement for our corporate offices, we were required to establish a letter of credit for the benefits of the landlord and to submit $4.5 million as a deposit for the letter of credit in October 2015. Subsequently, pursuant to the terms of the 1305 O’Brien Lease, at May 1, 2019, the $4.5 million in restricted cash was reduced to $4.0 million. As such, $4.0 million and $4.5 million was recorded in “Long-term restricted cash” in the consolidated balance sheet as of December 31, 2019 and 2018, respectively.

Pursuant to the terms of the O’Brien Lease, the letter of credit balance of $4.0 million at December 31, 2019 will be reduced again in May 2020 by $500,000, resulting in a letter of credit balance of $3.5 million.

Impairment of Long-Lived Assets

We periodically review property and equipment for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset is impaired or the estimated useful lives are no longer appropriate. Fair value is estimated based on discounted future cash flows. If indicators of impairment exist and the undiscounted projected cash flows associated with such assets are less than the carrying amount of the asset, an impairment loss is recorded to write the asset down to its estimated fair value. To date, we have not recorded any impairment charges.

Revenue Recognition

Our revenue is generated primarily from the sale of products and services. Product revenue primarily consists of sales of our instruments and related consumables; service and other revenue primarily consists of revenue earned from product maintenance agreements with some additional revenue from instrument lease agreements and grant revenue.

We account for a contract with a customer when there is a legally enforceable contract between us and the customer, the rights of the parties are identified, the contract has commercial substance, and collectability of the contract consideration is probable. Revenues are recognized when control of the promised goods or services is transferred to our customers or services are performed, in an amount that reflects the consideration we expect to be entitled to in exchange for those goods or services. Taxes we collect concurrent with revenue-producing activities are excluded from revenue.

Our instrument sales are generally sold in a bundled arrangement and commonly include the instrument, instrument accessories, installation, training, and consumables. Additionally, our instrument sale arrangements generally include a one-year period of service. For such bundled arrangements, we account for individual products and services separately if they are distinct, that is, if a product or service is separately identifiable from other items in the bundled package and if a customer can benefit from it on its own or with other resources that are readily available to the customer. Our customers cannot benefit from our instrument systems without installation, and installation can only be performed by us or qualified distributors. As a result, the system and installation are considered to be a single performance obligation recognized after installation is completed except for sales to qualified distributors, in which case the system is distinct and recognized when control has transferred to the distributor which typically occurs upon shipment.

The consideration for bundled arrangements is allocated between separate performance obligations based on their individual standalone selling price (“SSP”). The SSP is determined based on observable prices at which we separately sell the products and services. If a SSP is not directly observable, then we will estimate the SSP by considering multiple factors including, but not limited to, overall market conditions, including geographic or regional specific factors, internal costs, profit objectives, pricing practices and other observable inputs.

We recognize revenues as performance obligations are satisfied by transferring control of the product or service to the customer or over the term of a product maintenance agreement with a customer. Our revenue arrangements generally do not provide a right of return.

Contract liabilities and contract assets - Contract liabilities consist of deferred revenue. We record deferred revenues when cash payments are received or due in advance of our performance for product maintenance agreements. Deferred revenue is recognized over the related performance period, generally one to three years, on a straight-line basis as we are standing ready to provide services and a time-based measure of progress best reflects the satisfaction of the performance obligation.

As of December 31, 2019, we had a total of $0.6 million of deferred commissions included in “Prepaid expenses and other current assets” which is recognized as the related revenue is recognized. Additionally, as a practical expedient, we expense costs to obtain a contract as such costs are incurred if the amortization period would have been a year or less.

Contract assets as of December 31, 2019 and December 31, 2018 were not material.

Instrument lease agreements - Instrument leases are generally classified as operating-type leases and revenue from these leases is recognized on a straight-line basis over the respective lease term, once the lessee takes (or has the right to take) control/possession of the property under the lease. Effectively, this occurs once the installation is complete and control of the instrument is transferred to our customers.

Other practical expedients and exemptions - Customers generally are invoiced upon acceptance of the system, which is also the start of the one-year service period. As such, there is typically not more than a one-year difference between the receipt of cash and the provision of services. Therefore, we apply the practical expedient and do not account for any potential significant financing benefit. However, it is noted that some customers will pre-order extended service periods at the time of the initial system sale. These customers may choose to make quarterly or annual payments or prepay multiple years of service upfront but there is no pricing difference between these different payment options. As such, no significant financing component is believed to exist with any of our existing arrangements.

Cost of Revenue

Cost of revenue reflects the direct cost of product components, third-party manufacturing services and our internal manufacturing overhead and customer service infrastructure costs incurred to produce, deliver, maintain and support our instruments, consumables, and services. There are no incremental costs associated with our contractual revenue; all product development costs are reflected in research and development expense.

Manufacturing overhead is predominantly comprised of labor and facility costs. We determine and capitalize manufacturing overhead into inventory based on a standard cost model that approximates actual costs.

Service costs include the direct costs of components used in support, repair and maintenance of customer instruments as well as the cost of personnel, materials, shipping and support infrastructure necessary to support our installed customer base.

Research and Development

Research and development expense consists primarily of expenses for personnel engaged in the development of our SMRT Sequencing technology, the design and development of our future products and current product enhancements. These expenses also include prototype-related expenditures, development equipment and supplies, facilities costs and other related overhead. We expense research and development costs during the period in which the costs are incurred. However, we defer and capitalize non-refundable advance payments made for research and development activities until the related goods are received or the related services are rendered.

Operating Leases

We lease administrative, manufacturing and laboratory facilities under operating leases. Lease agreements may include rent holidays, rent escalation clauses and tenant improvement allowances. We recognize scheduled rent increases on a straight-line basis over the lease term beginning with the date we take possession of the leased space. Leasehold improvements are capitalized at cost and depreciated over the shorter of their expected useful life or the life of the lease. On January 1, 2019, we adopted ASC 842, which requires the recognition of the right-of-use assets and related operating and finance lease liabilities on the consolidated balance sheet. Prior to that, we recorded tenant improvement allowances as deferred rent liabilities and amortized the deferred rent over the term of the lease to rent expense on the statements of operations and comprehensive loss.

Leases with terms of 12 months or less are expensed on a straight-line basis over the term and are not recorded in the consolidated balance sheets.

Income Taxes

We account for income taxes under the asset and liability method, which requires, among other things, that deferred income taxes be provided for temporary differences between the tax bases of our assets and liabilities and the amounts reported in the financial statements. In addition, deferred tax assets are recorded for the future benefit of utilizing net operating losses and research and development credit carryforwards. A full valuation allowance is provided against our net deferred tax assets as it is more likely than not that the deferred tax assets will not be fully realized.

We review our positions taken relative to income taxes. To the extent our tax positions are more likely than not going to result in additional taxes, we would accrue the estimated amount of tax related to such uncertain positions.

Stock-Based Compensation

Stock-based Compensation

Stock-based compensation expense for all stock-based compensation awards, including stock options, restricted stock units, and shares issued under the 2010 Employee Stock Purchase Plan (“ESPP”), is based on the grant date fair value. The fair value for restricted stock units is based on grant date stock price, the fair value for stock option and ESPP shares is estimated using the Black-Scholes option pricing model with assumptions described in detail below:

Expected Term. Starting January 1, 2018, we determined the expected term using historical option experience. We determined expected term based on historical exercise patterns and an expectation of the time it will take for employees to exercise options still outstanding. Prior to 2018, we did not believe that we were able to rely on our historical employee exercise behavior to provide accurate data for estimating our expected term for use in determining the fair value of these options due to limited trading history. Therefore, for the period prior to 2018, the expected term of options is estimated based on the simplified method.

Expected Volatility. Starting January 1, 2018, we estimate the volatility of our common stock at the date of grant based on the historical volatility of our common stock. Prior to 2018, we did not have sufficient trading history to solely rely on the volatility of our own common stock for establishing expected volatility. Therefore, we based our expected volatility on the historical stock volatilities of our common stock as well as several comparable publicly listed companies over a period equal to the expected term of the options.

Risk-Free Rate. The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant for the expected term of the stock option.

Dividends. We have never paid any cash dividends on our common stock and we do not anticipate paying any cash dividends in the foreseeable future. Consequently, we use an expected dividend yield of zero in the Black-Scholes option valuation model.

Expected Forfeiture Rate. We estimate our forfeiture rate based on an analysis of our actual forfeitures and will continue to evaluate the adequacy of the forfeiture rate based on actual forfeiture experience, analysis of employee turnover behavior and other factors. The impact from a forfeiture rate adjustment will be recognized in full in the period of adjustment, and if the actual number of future forfeitures differs from that which was estimated, we may be required to record adjustments to stock-based compensation expense in future periods.

Other Comprehensive Income (Loss)

Other Comprehensive Income (loss)

Other comprehensive income (loss) is comprised of unrealized gains (losses) on our investment securities.

Recent Accounting Pronouncements

Recently Issued Accounting Standards

In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes. This ASU simplifies the accounting for income taxes by clarifying and amending existing guidance related to the recognition of franchise tax, the evaluation of a step up in the tax basis of goodwill, and the effects of enacted changes in tax laws or rates in the effective tax rate computation, among other clarifications. The standard will be effective for our annual reporting periods beginning after December 15, 2020, including interim reporting periods within those fiscal years. We are evaluating the impact of adopting this new accounting guidance on our consolidated financial statements.

In August 2018, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement. This ASU modifies the disclosure requirements on fair value measurements in Topic 820, Fair Value Measurement. The guidance is effective for annual and interim reporting periods beginning after December 15, 2019. We plan to adopt ASU 2018-13 on January 1, 2020. We have evaluated the effect that this guidance will have on our Consolidated Financial Statements and determined it will not have a material impact.

In June 2016, the Financial Accounting Standards Board, or FASB, issued ASU 2016-13, Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Instruments, or ASU 2016-13, which changes the impairment model for most financial assets. The new model uses a forward-looking expected loss method, which will generally result in earlier recognition of allowances for losses. ASU 2016-13 is effective for annual and interim periods beginning after December 15, 2019 and early adoption is permitted for annual and interim periods beginning after December 15, 2018. We plan to adopt ASU 2016-13 on January 1, 2020. We have evaluated the effect that this guidance will have on our Consolidated Financial Statements and determined it will not have a material impact.

Recently Adopted Accounting Standards

Adoption of ASU 2018-07

In June 2018, the FASB issued ASU 2018-07, Improvements to Nonemployee Share-Based Payment Accounting, to simplify the accounting for nonemployee share-based payment transactions by expanding the scope of Accounting Standards Codification, or ASC, Topic 718, Compensation - Stock Compensation, to include share-based payment transactions for acquiring goods and services from nonemployees. Under the new standard, most of the guidance on stock compensation payments to nonemployees would be aligned with the requirements for share-based payments granted to employees. We adopted this standard beginning on January 1, 2019 and the adoption of this standard did not have a material impact on our consolidated financial statements for the year ended December 31, 2019.

Adoption of ASU 2018-02

In February 2018, the FASB issued ASU 2018-02, Income Statement – Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income, that allows for an entity to elect to reclassify the income tax effects on items within accumulated other comprehensive income resulting from U.S. tax reform to retained earnings. We adopted this standard beginning on January 1, 2019 and the adoption of this standard did not have a material impact on our consolidated financial statements for the year ended December 31, 2019.

Adoption of ASC 842

On January 1, 2019, we adopted the FASB ASC, Topic 842, Leases, or ASC 842, which requires the recognition of the right-of-use assets and related operating and finance lease liabilities on the consolidated balance sheet. As permitted by ASC 842, we elected the adoption date of January 1, 2019, which is the date of initial application. As a result, the consolidated balance sheet prior to January 1, 2019 was not restated and continues to be reported under ASC Topic 840, Leases, or ASC 840, which did not require the recognition of right-of-use or operating lease liabilities on the consolidated balance sheet. The expense recognition for operating leases under ASC 842 is substantially consistent with ASC 840. As a result, there is no significant difference in our results of operations presented in our consolidated statements of operations and comprehensive loss for each period presented.

We adopted ASC 842 using a modified retrospective approach for leases existing at January 1, 2019. The adoption of ASC 842 had a substantial impact on our balance sheet. The most significant impact was the recognition of the operating lease right-of-use assets and the liability for operating leases. Accordingly, adoption of this standard resulted in the recognition of operating lease right-of-use assets of $35.5 million and operating lease liabilities of $49.2 million comprised of $3.4 million of current operating lease liabilities and $45.8 million of non-current operating lease liabilities on the consolidated balance sheet as of January 1, 2019.

As permitted under ASC 842, we elected several practical expedients that permit us:

to not reassess whether a contract is or contains a lease;

to not reassess the lease classification;

to not reassess the initial direct costs as of the adoption date;

to not recognize right-of-use assets and lease liabilities for short-term leases that have a term of 12 months or less; and

to not separate non-lease components for real estate leases.

The application of the practical expedients did not have a significant impact on the measurement of the operating lease liabilities.

Service and other revenue can include some revenue from instrument lease agreements. Instrument leases are generally classified as operating-type leases and revenue from these leases is recognized on a straight-line basis over the respective lease term. Lease income was not material in fiscal 2018 or for the year ended December 31, 2019.

Disclosures related to the amount and timing of cash flows arising from operating leases are included in “Leases” section of Note 7. Commitments and Contingencies.

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2019	Dec. 31, 2018
Consolidated Balance Sheets [Abstract]
Preferred Stock, par value	$ 0.001	$ 0.001
Preferred Stock, shares authorized	50,000,000	50,000,000
Preferred Stock, shares issued	0	0
Preferred Stock, shares outstanding	0	0
Common Stock, par value	$ 0.001	$ 0.001
Common Stock, shares authorized	1,000,000,000	1,000,000,000
Common Stock, shares issued	153,119,000	150,244,000
Common Stock, shares outstanding	153,119,000	150,244,000

Overview	12 Months Ended
Overview	Dec. 31, 2019
Overview [Abstract]
Overview	NOTE 1. OVERVIEW We design, develop and manufacture sequencing systems to help scientists resolve genetically complex problems. Based on our novel Single Molecule, Real-Time (SMRT®) sequencing technology, our products enable: de novo genome assembly to finish genomes in order to more fully identify, annotate and decipher genomic structures; full-length transcript analysis to improve annotations in reference genomes, characterize alternatively spliced isoforms in important gene families, and find novel genes; targeted sequencing to more comprehensively characterize genetic variations; and real-time kinetic information for epigenome characterization. Our technology provides high accuracy, ultra-long reads, uniform coverage and the ability to simultaneously detect epigenetic changes. PacBio® sequencing systems, including consumables and software, provide a simple and fast end-to-end workflow for SMRT sequencing. Our current products include the Sequel II instrument and SMRT Cell 8M, which together are capable of sequencing up to approximately eight million DNA molecules simultaneously, and the previous generation Sequel instrument and Sequel SMRT Cell 1M, which together are capable of sequencing up to approximately one million DNA molecules simultaneously. Our customers and our scientific collaborators have published numerous peer-reviewed articles in journals including Nature, Science, Cell, PNAS and The New England Journal of Medicine highlighting the power and applications of SMRT sequencing in projects such as finishing genomes, structural variation discovery, isoform transcriptome characterization, rare mutation discovery and the identification of chemical modifications of DNA related to virulence and pathogenicity. Our research and development efforts are focused on developing new products and further improving our existing products including continuing chemistry and sample preparation improvements to increase throughput and expand our supported applications. By providing access to genetic information that was previously inaccessible, we enable scientists to confidently increase their understanding of biological systems. PacBio® sequencing systems, including consumables and software, provide a simple and fast end-to-end workflow for SMRT sequencing. The names “Pacific Biosciences,” “PacBio,” “SMRT,” “SMRTbell,” “Sequel” and our logo are our trademarks.

Balance Sheet Components (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Balance Sheet Components [Line Items]
Depreciation	$ 7,265	$ 7,215	$ 8,442
Deferred revenue	9,600
Deferred revenue, current	7,610	6,537
Deferred revenue, non-current	$ 1,951	890
Minimum [Member]
Balance Sheet Components [Line Items]
Deferred revenue, non-current, period to be recognized	2 years
Maximum [Member]
Balance Sheet Components [Line Items]
Deferred revenue, non-current, period to be recognized	4 years
Product [Member] \| Cost of Goods and Cost of Service [Member]
Balance Sheet Components [Line Items]
Inventory reserves charged to cost of goods and cost of service	$ 5,100	2,000
Service and Other [Member] \| Cost of Goods and Cost of Service [Member]
Balance Sheet Components [Line Items]
Inventory reserves charged to cost of goods and cost of service	$ 500	$ 100

Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2019

Commitments and Contingencies [Abstract]

Schedule of Amount, Timing and Uncertainty of Cash Flows from Operating Leases



Maturity of Lease Liabilities	Amount
Years ending December 31,	(in thousands)
2020	$	7,150
2021		7,306
2022		7,488
2023		7,704
2024		7,920
Thereafter		23,598
Total undiscounted operating lease payments		61,166
Less: imputed interest		(15,365)
Present value of operating lease liabilities	$	45,801

Balance Sheet Classification
Operating lease liabilities, current	$	3,837
Operating lease liabilities, non-current		41,964
Total operating lease liabilities	$	45,801

Summary of Significant Accounting Policies (Summary of Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Assets
Total cash and cash equivalents	$ 29,627	$ 18,844
Total investments	19,472	83,510
Long-term restricted cash	4,000	4,500
Total assets measured at fair value	53,099	106,854
Liabilities
Financing derivative		16
Continuation Advances
Total liabilities measured at fair value		16
Cash and money market funds [Member]
Assets
Total cash and cash equivalents	18,644	18,844
Commercial paper [Member]
Assets
Total cash and cash equivalents	10,983
Commercial paper, not included with cash and cash equivalents [Member]
Assets
Total investments	16,971	53,469
Corporate debt securities [Member]
Assets
Total investments	2,501	10,214
U.S. government and agency securities, not included with cash and cash equivalents [Member]
Assets
Total investments		19,827
Level 1 [Member]
Assets
Total cash and cash equivalents	18,644	18,844
Long-term restricted cash	4,000	4,500
Total assets measured at fair value	22,644	23,344
Liabilities
Continuation Advances
Level 1 [Member] \| Cash and money market funds [Member]
Assets
Total cash and cash equivalents	18,644	18,844
Level 2 [Member]
Assets
Total cash and cash equivalents	10,983
Total investments	19,472	83,510
Total assets measured at fair value	30,455	83,510
Liabilities
Continuation Advances
Level 2 [Member] \| Commercial paper [Member]
Assets
Total cash and cash equivalents	10,983
Level 2 [Member] \| Commercial paper, not included with cash and cash equivalents [Member]
Assets
Total investments	16,971	53,469
Level 2 [Member] \| Corporate debt securities [Member]
Assets
Total investments	2,501	10,214
Level 2 [Member] \| U.S. government and agency securities, not included with cash and cash equivalents [Member]
Assets
Total investments		19,827
Level 3 [Member]
Liabilities
Financing derivative		16
Continuation Advances
Total liabilities measured at fair value		$ 16

Segment And Geographic Information

12 Months Ended

Dec. 31, 2019

Segment And Geographic Information [Abstract]

Segment And Geographic Information

NOTE 11. SEGMENT AND GEOGRAPHIC INFORMATION

We are organized as, and operate in, one reportable segment: the development, manufacturing and marketing of an integrated platform for genetic analysis. Our chief operating decision-maker is our Chief Executive Officer. The Chief Executive Officer reviews financial information presented on a consolidated basis for purposes of evaluating financial performance and allocating resources, accompanied by information about revenue by geographic regions. Our assets are primarily located in the United States of America and not allocated to any specific region and we do not measure the performance of geographic regions based upon asset-based metrics. Therefore, geographic information is presented only for revenue. Revenue by geographic region is based on the ship to address on the customer order.

A summary of our revenue by geographic location for the years ended December 31, 2019, 2018 and 2017 is as follows:



	Years Ended December 31,
(in thousands)	2019		2018		2017
North America	$	44,681	$	35,598	$	40,641
Europe (including the Middle East and Africa)		19,600		13,958		14,026
Asia Pacific		26,610		29,070		38,801
Total	$	90,891	$	78,626	$	93,468

A summary of our revenue by category for the years ended December 31, 2019, 2018 and 2017 is as follows:


	Year Ended December 31,
(in thousands)	2019		2018		2017
Instrument revenue	$	45,126	$	28,492	$	38,626
Consumable revenue		32,616		37,863		41,404
Product revenue		77,742		66,355		80,030
Service and other revenue		13,149		12,271		13,438
Total revenue	$	90,891	$	78,626	$	93,468

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2019

Income Taxes [Abstract]

Reconciliation of Federal Income Tax Rate



	Years ended December 31,
	2019		2018		2017
Statutory tax rate	21.0	%	21.0	%	35.0	%
State tax rate, net of federal benefit	4.9		3.5		8.6
Stock-based compensation	(0.8)		(1.6)		(1.9)
Tax credits	2.2		2.0		3.6
Remeasurement of deferred taxes due to tax reform	-		-		(123.3)
Other	0.2		(0.1)		0.3
Change in valuation allowance	(27.5)		(24.8)		77.7
Total	-	%	-	%	-	%

Reconciliation of Deferred Tax Assets and Liabilities



	December 31,
Deferred tax assets:	2019		2018
Net operating loss carryforwards	$	226,911	$	212,424
Research and development credits		45,853		42,635
Accruals and reserves		8,024		4,774
Stock-based compensation		16,219		14,582
Deferred rent		—		3,315
ASC842 Operating lease liability		10,837		—
Total deferred tax assets		307,844		277,730
Less: Valuation allowance		(298,658)		(275,540)
Total deferred tax assets:		9,186		2,190
Fixed assets		(1,425)		(2,190)
ASC842 Operating lease right-of-use assets		(7,761)		—
Total deferred tax liabilities		(9,186)		(2,190)
Net deferred tax assets	$	—	$	—

Reconciliation of Unrecognized Tax Benefit Accounts



Balance as of December 31, 2016	$	16,785
Decrease in balance related to tax positions taken in prior year		—
Increase in balance related to tax positions taken during current year		2,001
Balance as of December 31, 2017		18,786
Decrease in balance related to tax positions taken in prior year		—
Increase in balance related to tax positions taken during current year		1,661
Balance as of December 31, 2018	$	20,447
Decrease in balance related to tax positions taken in prior year		—
Increase in balance related to tax positions taken during current year		1,532
Balance as of December 31, 2019	$	21,979

Net Loss Per Share

12 Months Ended

Dec. 31, 2019

Net Loss Per Share [Abstract]

Net Loss Per Share

NOTE 10. NET LOSS PER SHARE

The following options outstanding, time-based RSUs and performance-based RSUs were excluded from the computation of diluted net loss per share for the periods presented because the effect of including such shares would have been antidilutive:



	Years Ended December 31,
(in thousands)	2019	2018	2017
Options to purchase common stock	22,697	25,176	25,404
RSUs with time-based vesting	1,086	371	—
RSUs with performance-based vesting	138	586	—

Cash and Cash Equivalents and Investments (Tables)

12 Months Ended

Dec. 31, 2019

Cash and Cash Equivalents and Investments [Abstract]

Summary of Cash, Cash Equivalents and Investments



	As of December 31, 2019
			Gross		Gross
	Amortized		unrealized		unrealized		Fair
	Cost		gains		losses		Value
Cash and cash equivalents:
Cash and money market funds	$	18,644	$	—	$	—	$	18,644
Commercial paper		10,983		—		—		10,983
Total cash and cash equivalents		29,627		—		—		29,627
Investments:
Commercial paper		16,971		1		(1)		16,971
Corporate debt securities		2,496		5		—		2,501
Total investments		19,467		6		(1)		19,472
Total cash, cash equivalents and investments	$	49,094	$	6	$	(1)	$	49,099

Long-term restricted cash:
Cash	$	4,000	$	—	$	—	$	4,000

	As of December 31, 2018
			Gross		Gross
	Amortized		unrealized		unrealized		Fair
	Cost		gains		losses		Value
Cash and cash equivalents:
Cash and money market funds	$	18,844	$	—	$	—	$	18,844
Total cash and cash equivalents		18,844		—		—		18,844
Investments:
Commercial paper		53,493		—		(24)		53,469
Corporate debt securities		10,223		3		(12)		10,214
US government & agency securities		19,830		—		(3)		19,827
Total investments		83,546		3		(39)		83,510
Total cash, cash equivalents and investments	$	102,390	$	3	$	(39)	$	102,354

Long-term restricted cash:
Cash	$	4,500	$	—	$	—	$	4,500

Summary of Contractual Maturities of Cash Equivalents and Available-for-Sale Investments



(in thousands)	Fair Value
Due in one year or less	$	30,455
Due after one year through five years		—
Total	$	30,455

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue:
Revenue	$ 90,891	$ 78,626	$ 93,468
Cost of Revenue:
Cost of revenue	56,315	53,530	58,809
Gross profit	34,576	25,096	34,659
Operating Expense:
Research and development	59,630	62,594	65,324
Sales, general and administrative	75,491	63,489	59,119
Total operating expense	135,121	126,083	124,443
Operating loss	(100,545)	(100,987)	(89,784)
Gain from Continuation Advances from Illumina	18,000
Interest expense	(2,611)	(2,423)	(2,921)
Other income, net	1,022	848	516
Net loss	(84,134)	(102,562)	(92,189)
Other comprehensive loss:
Unrealized gain (loss) on investments	41	(4)	(37)
Comprehensive loss	$ (84,093)	$ (102,566)	$ (92,226)
Net loss per share:
Basic and diluted net loss per share	$ (0.55)	$ (0.76)	$ (0.87)
Shares used in computing basic and diluted net loss per share	152,527,000	135,094,000	105,682,000
Product [Member]
Revenue:
Revenue	$ 77,742	$ 66,355	$ 80,030
Cost of Revenue:
Cost of revenue	44,771	42,053	42,900
Service and Other [Member]
Revenue:
Revenue	13,149	12,271	13,438
Cost of Revenue:
Cost of revenue	$ 11,544	$ 11,477	$ 15,909

Stockholders' Equity (Schedule of Fair Value of Employee Stock Purchase Plan) (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Dividend yield	0.00%
ESPP [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected volatility			70.00%
Risk-free interest rate, minimum		1.30%	0.80%
Risk-free interest rate, maximum		2.70%	1.40%
Dividend yield
ESPP [Member] \| Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term in years		6 months	6 months
Expected volatility		65.00%
ESPP [Member] \| Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term in years		2 years	2 years
Expected volatility		67.00%

Subsequent Events	12 Months Ended
Subsequent Events	Dec. 31, 2019
Subsequent Events [Abstract]
Subsequent Events	NOTE 13. SUBSEQUENT EVENTS On January 2, 2020, we, Illumina and Merger Subsidiary entered into the Termination Agreement. As part of our agreement to terminate the Merger Agreement, Illumina subsequently paid us a $98.0 million termination fee, from which we expect to pay our financial advisor associated fees of approximately $10 million. In addition, as previously agreed to pursuant to the terms of the Merger Agreement, Illumina paid us additional Continuation Advances of $6 million in January 2020 and $22 million in February 2020 and is scheduled to make a final Continuation Advance to us of $6 million in March 2020. However, pursuant to the Termination Agreement, in the event that, on or prior to September 30, 2020, we enter into a definitive agreement providing for, or consummate, a Change of Control Transaction (as defined in the Termination Agreement), then we will repay the Reverse Termination Fee (without interest) to Illumina in connection with the consummation of such Change of Control Transaction. If such Change of Control Transaction is not consummated by the two-year anniversary of the execution of the definitive agreement for such Change of Control Transaction, then we will not be required to repay the Reverse Termination Fee. In addition, up to the full amount of the Continuation Advances paid to us are repayable without interest to Illumina if, within two years of March 31, 2020, we enter into a Change of Control Transaction or raise at least $100 million in equity in a single transaction or debt financing (may have multiple closings), with the amount repayable dependent on the amount raised by us. In February 2020, upon the maturity of the Facility Agreement, we repaid the remaining outstanding principal of $16.0 million and interest to Deerfield.

Segment And Geographic Information (Narrative) (Details)	12 Months Ended
	Dec. 31, 2019 segment
Segment And Geographic Information [Abstract]
Number of reportable segments	1

Net Loss Per Share (Tables)

12 Months Ended

Dec. 31, 2019

Net Loss Per Share [Abstract]

Antidilutive Shares Excluded from Computation of Diluted Net Loss per Share



	Years Ended December 31,
(in thousands)	2019	2018	2017
Options to purchase common stock	22,697	25,176	25,404
RSUs with time-based vesting	1,086	371	—
RSUs with performance-based vesting	138	586	—

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2019

Summary of Significant Accounting Policies [Abstract]

Summary of Significant Accounting Policies

NOTE 3. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Basis of Presentation and Consolidation

Use of Estimates

Accounting changes

the expense recognition for operating leases under ASC 842 remained substantially consistent with ASC 840.

Fair Value of Financial Instruments

Level 1: quoted prices in active markets for identical assets or liabilities;

Level 3: unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.

Assets and Liabilities Measured at Fair Value on a Recurring Basis

The following table sets forth the fair value of our financial assets and liabilities that were measured on a recurring basis as of December 31, 2019 and 2018, respectively (in thousands):



	December 31, 2019								December 31, 2018
(in thousands)	Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
Assets
Cash and cash equivalents:
Cash and money market funds	$	18,644	$	—	$	—	$	18,644	$	18,844	$	—	$	—	$	18,844
Commercial paper		—		10,983		—		10,983		—		—		—		—
Total cash and cash equivalents		18,644		10,983		—		29,627		18,844		—		—		18,844
Investments:
Commercial paper		—		16,971		—		16,971		—		53,469		—		53,469
Corporate debt securities		—		2,501		—		2,501		—		10,214		—		10,214
US government & agency securities		—		—		—		—		—		19,827		—		19,827
Total investments		—		19,472		—		19,472		—		83,510		—		83,510
Long-term restricted cash:
Cash		4,000		—		—		4,000		4,500		—		—		4,500
Total assets measured at fair value	$	22,644	$	30,455	$	—	$	53,099	$	23,344	$	83,510	$	—	$	106,854

Liabilities
Financing derivative	$	—	$	—	$	—	$	—	$	—	$	—	$	16	$	16
Continuation Advances		—		—		—		—		—		—		—		—
Total liabilities measured at fair value	$	—	$	—	$	—	$	—	$	—	$	—	$	16	$	16

Estimated fair value of the Financing Derivative liability

The following table provides the changes in the fair value of the Financing Derivative for the years ended December 31, 2019 and 2018 (in thousands), respectively:



Financing Derivative	Amount
Balance as of December 31, 2017	$	183
Gain on change in fair value of Financing Derivative		(167)
Balance as of December 31, 2018		16
Gain on change in fair value of Financing Derivative		(16)
Balance as of December 31, 2019	$	—

Estimated fair value of the Continuation Advances liability

We enter into a Change of Control Transaction (as defined in the Termination Agreement) within two years following March 31, 2020;

We raise $100 million or more in a single equity or debt financing (that may have multiple closings) within two years following March 31, 2020.

Financial Assets and Liabilities Not Measured at Fair Value on a Recurring Basis



	December 31, 2019				December 31, 2018
	Fair Value		Carrying Value		Fair Value		Carrying Value
Long-term notes payable	$	16,038	$	15,871	$	15,915	$	14,659

Cash and Cash Equivalents

We consider all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents.

Investments

Concentration and Other Risks

For the years ended December 31, 2019, 2018 and 2017, one customer, Gene Company Limited, accounted for approximately 17%, 26% and 31% of our total revenue, respectively.

Inventory

Property and Equipment, Net

Long-term Restricted Cash

Impairment of Long-Lived Assets

Revenue Recognition

Contract assets as of December 31, 2019 and December 31, 2018 were not material.

Cost of Revenue

Research and Development

Operating Leases

Leases with terms of 12 months or less are expensed on a straight-line basis over the term and are not recorded in the consolidated balance sheets.

Income Taxes

Stock-based Compensation

Risk-Free Rate. The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant for the expected term of the stock option.

Other Comprehensive Income (loss)

Other comprehensive income (loss) is comprised of unrealized gains (losses) on our investment securities.

Recent Accounting Pronouncements

Recently Issued Accounting Standards

Recently Adopted Accounting Standards

Adoption of ASU 2018-07

Adoption of ASU 2018-02

Adoption of ASC 842

As permitted under ASC 842, we elected several practical expedients that permit us:

to not reassess whether a contract is or contains a lease;

to not reassess the lease classification;

to not reassess the initial direct costs as of the adoption date;

to not recognize right-of-use assets and lease liabilities for short-term leases that have a term of 12 months or less; and

to not separate non-lease components for real estate leases.

The application of the practical expedients did not have a significant impact on the measurement of the operating lease liabilities.

Disclosures related to the amount and timing of cash flows arising from operating leases are included in “Leases” section of Note 7. Commitments and Contingencies.

Balance Sheet Components

12 Months Ended

Dec. 31, 2019

Balance Sheet Components [Abstract]

Balance Sheet Components

NOTE 5. BALANCE SHEET COMPONENTS

Inventory

As of December 31, 2019 and 2018, our inventory consisted of the following components:



	December 31,
(in thousands)	2019		2018
Purchased materials	$	3,966	$	6,222
Work in process		4,594		7,341
Finished goods		4,752		4,315
Inventory	$	13,312	$	17,878

For the year ended December 31, 2019, approximately $5.1 million and $0.5 million of inventory reserves due to excess or obsolesce were charged to cost of goods and cost of service, respectively. For the year ended December 31, 2018 approximately $2.0 million and $0.1 million of inventory reserves due to excess or obsolesce were charged to cost of goods and cost of service, respectively.

Property and Equipment, Net

As of December 31, 2019 and 2018, our property and equipment, net, consisted of the following components:



	December 31,
(in thousands)	2019		2018
Laboratory equipment and machinery	$	25,173	$	24,111
Leasehold improvements		29,902		29,821
Computer equipment		11,851		9,484
Software		4,747		4,734
Furniture and fixtures		2,422		2,422
Construction in progress		193		608
		74,288		71,180
Less: Accumulated depreciation		(44,218)		(37,107)
Property and equipment, net	$	30,070	$	34,073

Depreciation expense during the years ended December 31, 2019, 2018 and 2017was $7.3 million, $7.2 million and $8.4 million, respectively.

Accrued Expenses

As of December 31, 2019 and 2018, our accrued expenses consisted of the following components:



	December 31,
(in thousands)	2019		2018
Salaries and benefits	$	9,748	$	8,523
Accrued product development costs		67		561
Accrued Tenant Improvements for Menlo Park building		998		694
Inventory accrual		229		499
Accrued professional services and legal fees		943		1,588
Other		1,257		958
Accrued expenses	$	13,242	$	12,823

Deferred Revenue

As of December 31, 2019, we had a total of $9.6 million of deferred revenue from our service contracts, $7.6 million of which was recorded as “deferred revenue, current” to be recognized over the next year and the remaining $2.0 million was recorded as “deferred revenue, non-current” to be recognized in the next 2 to 4 years.

Revenue recognized during the year ended December 31, 2019 includes $6.5 million of previously deferred revenue that was included in “deferred revenue, current” as of December 31, 2018.

Net Loss Per Share (Antidilutive Shares Excluded From Computation Of Diluted Net Loss Per Share) (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Options outstanding [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from the computation of earnings per share	22,697	25,176	25,404
Time-Based Restricted Stock Units (RSUs) [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from the computation of earnings per share	1,086	371
Performance-Based Restricted Stock Units (RSUs) [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from the computation of earnings per share	138	586

Commitments and Contingencies (Schedule of Amount, Timing and Uncertainty of Cash Flows from Operating Leases) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jan. 01, 2019
Maturity of Lease Liabilities
2020	$ 7,150
2021	7,306
2022	7,488
2023	7,704
2024	7,920
Thereafter	23,598
Total undiscounted operating lease payments	61,166
Less: imputed interest	(15,365)
Present value of operating lease liabilities	45,801	$ 49,200
Balance Sheet Classification
Operating lease liabilities, current	3,837	3,400
Operating lease liabilities, non-current	41,964	45,800
Total operating lease liabilities	$ 45,801	$ 49,200

Segment And Geographic Information (Tables)

12 Months Ended

Dec. 31, 2019

Segment And Geographic Information [Abstract]

Schedule of Revenue by Geographic Location



	Years Ended December 31,
(in thousands)	2019		2018		2017
North America	$	44,681	$	35,598	$	40,641
Europe (including the Middle East and Africa)		19,600		13,958		14,026
Asia Pacific		26,610		29,070		38,801
Total	$	90,891	$	78,626	$	93,468

Summary of Revenue by Category


	Year Ended December 31,
(in thousands)	2019		2018		2017
Instrument revenue	$	45,126	$	28,492	$	38,626
Consumable revenue		32,616		37,863		41,404
Product revenue		77,742		66,355		80,030
Service and other revenue		13,149		12,271		13,438
Total revenue	$	90,891	$	78,626	$	93,468

Stockholders' Equity (Schedule of Fair Value of Employee Stock Options) (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Dividend yield	0.00%
Options outstanding [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term in years		5 years 2 months 12 days	6 years 1 month 6 days
Expected volatility		66.80%	70.00%
Risk-free interest rate		2.60%	2.10%
Dividend yield

Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2019

Stockholders' Equity [Abstract]

Summary of Stock Option Activity



	Stock Options Outstanding
	Number			Weighted average
	of shares	Exercise price		exercise price
Balances, December 31, 2018	25,176	$	1.16 – 16.00	$	5.66
Additional shares reserved
Options granted	—		—		—
Options exercised	(1,199)	$	1.16 – 7.05	$	4.78
Options canceled	(1,280)	$	2.54 – 16.00	$	8.01
Balances, December 31, 2019	22,697	$	1.16 – 16.00	$	5.57

Reconciliation of Outstanding and Exercisable Stock Options



		Options Outstanding				Options Exercisable
			Weighted average
		Number	remaining contractual	Weighted average		Number	Weighted average
Exercise price		outstanding	life (Years)	exercise price		vested	exercise price
$	0.00 – 1.60	414,207	2.87	$	1.18	414,207	$	1.18
$	1.60 – 3.20	5,720,080	6.38	$	2.54	3,680,040	$	2.54
$	3.20 – 4.80	3,110,896	3.88	$	4.02	2,858,193	$	4.02
$	4.80 – 6.40	5,935,013	6.12	$	5.46	4,895,635	$	5.46
$	6.40 – 8.00	2,554,434	5.19	$	7.21	2,525,441	$	7.21
$	8.00 – 9.60	3,061,742	4.63	$	8.77	2,938,483	$	8.77
$	9.60 – 11.20	1,224,700	4.94	$	10.20	1,224,700	$	10.20
$	11.20 – 12.80	423,252	1.08	$	12.10	423,252	$	12.10
$	12.80 – 14.40	163,250	1.00	$	13.71	163,210	$	13.71
$	14.40 – 16.00	89,000	0.80	$	15.99	89,000	$	15.99
		22,696,574	5.30	$	5.57	19,212,161	$	5.90

Summary of Time-Based RSUs Activity


		Weighted average
	Number	grant date
	of shares	fair value
RSUs outstanding at December 31, 2018	371	$	3.20
RSUs granted	900		7.06
RSUs vested	(127)		4.35
RSUs forfeited	(58)		5.86
Unvested RSUs outstanding at December 31, 2019	1,086	$	6.12

Summary of Performance-Based RSUs Activity


		Weighted average
	Number	grant date
	of shares	fair value
PSUs outstanding at December 31, 2018	586	$	2.58
PSUs granted	—		—
PSUs vested	(204)		2.57
PSUs forfeited	(244)		2.57
Unvested PSUs outstanding at December 31, 2019	138	$	2.63

Schedule of Stock-Based Compensation Expense



	Years Ended December 31,
	2019		2018		2017
Cost of revenue	$	1,857	$	3,124	$	2,311
Research and development		7,699		10,076		8,506
Sales, general and administrative		6,845		9,953		9,535
Total stock-based compensation expense	$	16,401	$	23,153	$	20,352

Schedule of Fair Value of Employee Stock Options



	Years Ended December 31,
	2019		2018		2017
Expected term (years)		—		5.2 years		6.1 years
Expected volatility		—		66.8%		70.0%
Risk-free interest rate		—		2.6%		2.1%
Dividend yield		—		—		—

Schedule of Fair Value of Employee Stock Purchase Plan



	Years Ended December 31,
	2019		2018		2017
Expected term (years)		—		0.5 - 2.0		0.5 - 2.0
Expected volatility		—		65% - 67%		70.0%
Risk-free interest rate		—		1.3%-2.7%		0.8%-1.4%
Dividend yield		—		—		—

Consolidated Statements of Cash Flows $ in Thousands	12 Months Ended
Consolidated Statements of Cash Flows $ in Thousands	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Cash flows from operating activities
Net loss	$ (84,134)	$ (102,562)	$ (92,189)
Adjustments to reconcile net loss to net cash used in operating activities
Gain from Continuation Advances from Illumina	(18,000)
Depreciation	7,265	7,215	8,442
Amortization of right-of-use assets	2,683
Amortization of debt discount and financing costs	1,212	1,024	1,203
Stock-based compensation	16,401	23,153	20,352
(Gain) loss from derivative	(16)	(167)	653
Amortization and accretion for investment premium (discount)	(913)	(758)	(32)
Loss on disposition of equipment	194		11
Loss on return of building under capital lease			68
Changes in assets and liabilities
Accounts receivable	(6,671)	4,838	(2,012)
Inventory	3,915	3,623	(8,442)
Prepaid expenses and other assets	(523)	(290)	7,803
Accounts payable	1,713	(2,239)	764
Accrued expenses	419	205	(3,986)
Deferred revenue	2,134	33	(1,033)
Operating lease liabilities	(3,428)
Other liabilities	(563)	(505)	880
Net cash used in operating activities	(78,312)	(66,430)	(67,518)
Cash flows from investing activities
Purchase of property and equipment	(2,836)	(1,854)	(10,433)
Proceeds from disposal of property and equipment			41
Purchase of investments	(57,727)	(122,183)	(86,339)
Sales of investments	1,500	2,442	7,111
Maturities of investments	121,110	83,180	88,071
Net cash provided by (used in) investing activities	62,047	(38,415)	(1,549)
Cash flows from financing activities
Continuation Advances from Illumina	18,000
Proceeds from issuance of common stock from equity plans	8,548	9,652	8,914
Notes payable principal payoff			(4,500)
Net cash provided by financing activities	26,548	107,182	68,809
Net increase (decrease) in cash and cash equivalents and restricted cash	10,283	2,337	(258)
Cash and cash equivalents and restricted cash at beginning of period	23,344	21,007	21,265
Cash and cash equivalents and restricted cash at end of period	33,627	23,344	21,007
Cash and cash equivalents at end of period	29,627	18,844	16,507
Restricted cash at end of period	4,000	4,500	4,500
Supplemental disclosure of cash flow information
Interest paid	1,400	1,400	1,687
Supplemental disclosure of non-cash investing and financing activities
Inventory transferred to property and equipment	2,062	1,871	1,267
Property and equipment transfered to inventory	$ (1,536)	(343)	(261)
Property and equipment paid for by landlord			12,600
Changes in deposits for property and equipment paid in prior period			9,694
Property and equipment returned to landlord			1,854
At the Market Offering [Member]
Cash flows from financing activities
Proceeds from issuance of common stock from offering, net of issuance costs			11,865
Underwritten Public Equity Offering [Member]
Cash flows from financing activities
Proceeds from issuance of common stock from offering, net of issuance costs		$ 97,530	$ 52,530

Balance Sheet Components (Components of Property and Equipment, Net) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property and equipment	$ 74,288	$ 71,180
Less: Accumulated depreciation	(44,218)	(37,107)
Property and equipment, net	30,070	34,073
Laboratory Equipment And Machinery [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	25,173	24,111
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	29,902	29,821
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	11,851	9,484
Software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	4,747	4,734
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	2,422	2,422
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	$ 193	$ 608

Summary of Significant Accounting Policies (Narrative) (Details)		1 Months Ended			3 Months Ended	12 Months Ended
	Mar. 20, 2020 USD ($)	May 31, 2020 USD ($)	Mar. 31, 2020 USD ($)	Feb. 29, 2020 USD ($)	Dec. 31, 2019 USD ($) customer	Dec. 31, 2019 USD ($) customer	Dec. 31, 2018 USD ($) customer	Dec. 31, 2017 USD ($) customer $ / shares	May 01, 2019 USD ($)	Jan. 01, 2019 USD ($)	Oct. 31, 2015 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Charge to cost of service and other revenue related to change in estimated useful life of lease instruments								$ 1,600,000
Charge to cost of service and other revenue related to change in estimated useful life of lease instruments, impact on earnings per share \| $ / shares								$ (0.01)
Continuation Advances from Illumina					$ 18,000,000	$ 18,000,000
Period in which company must repay continuation advances if change-of-controll transaction is entered into with third party						2 years
Equity or debt financing that must be raised in a single transaction						$ 100,000,000
Gain from Continuation Advances from Illumina					18,000,000	18,000,000
Contingent repayment liability					$ 0	0
Fair value assets/liabilities transfer between levels						$ 0
Future cash flows weighted average market yield					6.50%	6.50%	9.60%
Investments impariment charges						$ 0	$ 0	$ 0
Long-term restricted cash					$ 4,000,000	4,000,000	4,500,000		$ 4,000,000		$ 4,500,000
Long-lived assets impairment charges						$ 0
Service period						1 year
Dividend yield						0.00%
Prepaid expenses and other current assets					3,369,000	$ 3,369,000	$ 2,832,000
Operating lease right-of-use assets, net					32,827,000	32,827,000				$ 35,500,000
Operating lease liability					45,801,000	45,801,000				49,200,000
Operating lease liabilities, current					3,837,000	3,837,000				3,400,000
Operating lease liabilities, non-current					$ 41,964,000	$ 41,964,000				$ 45,800,000
Forecast [Member]
Summary Of Significant Accounting Policies [Line Items]
Continuation Advances from Illumina			$ 6,000,000	$ 22,000,000
Period in which company must repay continuation advances if change-of-controll transaction is entered into with third party	2 years
Equity or debt financing that must be raised in a single transaction	$ 100,000,000
Period in which company must raise equity or debt financing in a single transaction	2 years
Long-term restricted cash		$ 3,500,000
Decrease in Long-term restricted cash		$ 500,000
Sales Revenue, Net [Member] \| Gene Company Limited [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of individual customers \| customer					1	1	1	1
Concentration risk, percentage						17.00%	26.00%	31.00%
Accounts Receivable [Member] \| Domestic Customers [Member]
Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage						55.00%	50.00%
Accounts Receivable [Member] \| Gene Company Limited [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of individual customers \| customer					1	1	1
Concentration risk, percentage						11.00%	14.00%
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Deferred service revenue, performance period						1 year
Minimum [Member] \| Computer Equipment [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life						2 years
Minimum [Member] \| Software [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life						3 years
Minimum [Member] \| Furniture and Fixtures [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life						3 years
Minimum [Member] \| Lab Equipment [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life						3 years
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Deferred service revenue, performance period						3 years
Maximum [Member] \| Computer Equipment [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life						3 years
Maximum [Member] \| Software [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life						5 years
Maximum [Member] \| Furniture and Fixtures [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life						7 years
Maximum [Member] \| Lab Equipment [Member]
Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life						5 years
Deferred Commission [Member]
Summary Of Significant Accounting Policies [Line Items]
Prepaid expenses and other current assets					$ 600,000	$ 600,000

Notes Payable (Narrative) (Details)		1 Months Ended			12 Months Ended
Notes Payable (Narrative) (Details)	Jun. 23, 2017 USD ($) item	Feb. 29, 2020 USD ($)	Jun. 30, 2017 USD ($) item	Feb. 28, 2013 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2018 USD ($)
Debt Instrument [Line Items]
Percentage of net proceeds from out side financing or equity component				25.00%
Repayment of notes payable						$ 4,500,000
Notes payable, current					$ 15,871,000
Future cash flows weighted average market yield					6.50%		9.60%
Fair value of the financing derivative					$ 0	$ 183,000	$ 16,000
Notes payable, non-current							14,659,000
Facility Agreement [Member]
Debt Instrument [Line Items]
Proceeds from issuance of debt				$ 20,500,000
Facility agreement period				7 years
Proceeds from issuance of debt agreement, net of issuance costs				$ 20,000,000
Facility fee				500,000
Notes payable, current					16,000,000
Cash and cash equivalent minimum amount quarterly required				2,000,000
Notes [Member]
Debt Instrument [Line Items]
Principal amount of notes				$ 20,500,000
Debt instrument, stated interest rate				8.75%
Percentage of net proceeds from out side financing or equity component	25.00%
Repayment of notes payable	$ 4,500,000		$ 4,500,000
Number of Notes holders paid \| item	1		1
Aggregate principal amount					16,000,000		16,000,000
Debt discount that has yet to be amortized					$ 200,000		1,300,000
Maturity date					Dec. 31, 2020
Notes payable, non-current					$ 15,800,000		$ 14,700,000
Forecast [Member]
Debt Instrument [Line Items]
Repayment of notes payable		$ 16,000,000

Subsequent Events (Narrative) (Details) - USD ($) $ in Thousands			1 Months Ended			3 Months Ended	12 Months Ended
	Mar. 20, 2020	Jan. 02, 2020	Mar. 31, 2020	Feb. 29, 2020	Jan. 31, 2020	Dec. 31, 2019	Dec. 31, 2019	Dec. 31, 2017
Continuation Advances from Illumina						$ 18,000	$ 18,000
Period in which company must repay continuation advances if change-of-controll transaction is entered into with third party							2 years
Equity or debt financing that must be raised in a single transaction							$ 100,000
Repayment of notes payable								$ 4,500
Forecast [Member]
Continuation Advances from Illumina			$ 6,000	$ 22,000
Period in which company must repay continuation advances if change-of-controll transaction is entered into with third party	2 years
Period in which company must raise equity or debt financing in a single transaction	2 years
Equity or debt financing that must be raised in a single transaction	$ 100,000
Repayment of notes payable				$ 16,000
Subsequent Event [Member]
Termination fee received		$ 98,000
Advisor fee payable		$ 10,000
Continuation Advances from Illumina					$ 6,000

Cash and Cash Equivalents and Investments (Summary of Cash, Cash Equivalents and Investments) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Cash, cash equivalents and investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	$ 49,094	$ 102,390
Gross unrealized gains	6	3
Gross unrealized losses	(1)	(39)
Fair value	49,099	102,354
Cash and cash equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	29,627	18,844
Fair value	29,627	18,844
Cash and money market funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	18,644	18,844
Fair value	18,644	18,844
Commercial paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	10,983
Fair value	10,983
Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	19,467	83,546
Gross unrealized gains	6	3
Gross unrealized losses	(1)	(39)
Fair value	19,472	83,510
Commercial paper, not included with cash and cash equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	16,971	53,493
Gross unrealized gains	1
Gross unrealized losses	(1)	(24)
Fair value	16,971	53,469
Corporate debt securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	2,496	10,223
Gross unrealized gains	5	3
Gross unrealized losses		(12)
Fair value	2,501	10,214
U.S. government and agency securities, not included with cash and cash equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost		19,830
Gross unrealized losses		(3)
Fair value		19,827
Cash [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	4,000	4,500
Fair value	$ 4,000	$ 4,500

Stockholders' Equity (Narrative) (Details) $ / shares in Units, $ in Thousands		1 Months Ended			3 Months Ended	12 Months Ended
	Jun. 23, 2017 USD ($) item	Jan. 31, 2020 shares	Jan. 31, 2019 shares	Jun. 30, 2017 USD ($) $ / shares item shares	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) item $ / shares shares	Dec. 31, 2018 USD ($) $ / shares item shares	Dec. 31, 2017 USD ($) $ / shares shares	Aug. 31, 2017 USD ($)	Oct. 31, 2010 $ / shares shares
Stockholders' Equity [Line Items]
Common Stock, shares authorized \| shares					1,000,000,000	1,000,000,000	1,000,000,000			1,000,000,000
Common Stock, par value \| $ / shares					$ 0.001	$ 0.001	$ 0.001			$ 0.001
Preferred Stock, shares authorized \| shares					50,000,000	50,000,000	50,000,000			50,000,000
Preferred Stock, par value \| $ / shares					$ 0.001	$ 0.001	$ 0.001			$ 0.001
Preferred Stock, shares issued \| shares					0	0	0
Preferred Stock, shares outstanding \| shares					0	0	0
Common stock, dividends declared \| $ / shares						$ 0
Voting right of common stock share holders						one
Voting right of common stock share holdes, number of votes \| item						1
Amount of common stock, preferred stock, depositiry shares, warrants, units or debt securities available in future public offerings									$ 150,000
Repayment of notes payable								$ 4,500
Number of equity compensation plans \| item						2
Accelerated compensation					$ 2,500
Aggregate intrinsic value outstanding						$ 20,000
Aggregate intrinsic value exercisable options						$ 14,500
Stock price \| $ / shares						$ 5.14
Weighted average remaining contractual life for exercisable						4 years 10 months 10 days
Vested and expected to vest, outstanding \| shares						21,231,000
Vested and expected to vest, aggregate intrinsic value						$ 17,800
Vested and expected to vest, weighted average exercise price \| $ / shares						$ 5.69
Vested and expected to vest, weighted average remaining contractual life						5 years 1 month 17 days
Total intrinsic value of options exercised						$ 2,600	$ 5,300	1,700
Fair value of options vested						2,900	3,900	6,400
Stock-based compensation cost capitalized in inventory						300	700
Stock-based compensation						$ 16,401	$ 23,153	$ 20,352
2010 Plan [Member]
Stockholders' Equity [Line Items]
Stock option grant, term						10 years
Stock option grant, vest						4 years
Stock option grant, vest rate upon first anniversary						25.00%
Stock option grant, vest rate per month thereafter						2.08%
Vesting period						4 years
2010 Director Plan [Member]
Stockholders' Equity [Line Items]
Stock option grant, term						10 years
Stock option grant, vest rate upon first anniversary						33.00%
Stock option grant, vest rate per month thereafter						2.78%
2010 Director Plan [Member] \| Minimum [Member]
Stockholders' Equity [Line Items]
Stock option grant, vest						1 year
Vesting period						1 year
2010 Director Plan [Member] \| Maximum [Member]
Stockholders' Equity [Line Items]
Stock option grant, vest						3 years
Vesting period						3 years
2010 Plan and 2010 Director Plan [Member]
Stockholders' Equity [Line Items]
Common stock reserved for issuance \| shares					11,300,000	20,500,000	11,300,000
ESPP [Member]
Stockholders' Equity [Line Items]
Common stock reserved for issuance \| shares						3,651,066
Additional common stock reserved for issuance \| shares			3,100,000
Percentage of outstanding common stock used to determine annual plan increase						2.00%
Number of purchase periods \| item						4
Purchase period of ESPP						6 months
Percentage of fair market value at which stock can be purchased						85.00%
Weighted average fair value at grant date \| $ / shares						$ 0	$ 1.47	$ 2.28
Stock-based compensation						$ 500	$ 6,800	$ 3,100
Common stock purchased under plan \| shares						1,306,329	1,674,960	1,289,663
Cash received from option exercises						$ 2,700	$ 3,400	$ 5,300
At the Market Offering [Member]
Stockholders' Equity [Line Items]
Shares issued \| shares								3,200,000
Average common stock price per share \| $ / shares								$ 3.86
Proceeds from issuance of common stock from offering, net of issuance costs								$ 11,865
Commissions, percentage of gross proceeds				3.00%
At the Market Offering [Member] \| Common Stock
Stockholders' Equity [Line Items]
Shares issued \| shares								3,171,000
Underwritten Public Equity Offering [Member]
Stockholders' Equity [Line Items]
Shares issued \| shares				17,700,000			30,600,000
Proceeds from issuance of common stock from offering, net of issuance costs				$ 52,500			$ 97,530	$ 52,530
Commissions, percentage of gross proceeds				4.00%
Holders may elect to receive net proceeds from financing activities, percentage						25.00%
Number of offerings \| item							2
Price per share \| $ / shares				$ 3.10	$ 3.38		$ 3.38
Underwritten Public Equity Offering [Member] \| Common Stock
Stockholders' Equity [Line Items]
Shares issued \| shares							30,610,000	17,732,000
Options outstanding [Member]
Stockholders' Equity [Line Items]
Exercise price, lower range \| $ / shares
Weighted average remaining contractual life						1 year 6 months
Weighted average fair value at grant date \| $ / shares						$ 1.50	$ 3.08
Stock-based compensation						$ 11,000	$ 15,500	$ 17,200
Options granted \| shares
Unrecognized compensation costs						$ 5,600
Cash received from option exercises						$ 5,900	$ 6,300	$ 3,600
Options outstanding [Member] \| $1.16 – 16.00 [Member]
Stockholders' Equity [Line Items]
Exercise price, lower range \| $ / shares						$ 1.16	$ 1.16
Exercise price, upper range \| $ / shares						$ 16.00	$ 16.00
Options outstanding [Member] \| $2.54 – 16.00 [Member]
Stockholders' Equity [Line Items]
Options expired \| shares						900,000
Exercise price, lower range \| $ / shares						$ 2.54
Exercise price, upper range \| $ / shares						16.00
Options expired, weighted average exercise price \| $ / shares						$ 9.90
Time-Based Restricted Stock Units (RSUs) [Member]
Stockholders' Equity [Line Items]
Stock option grant, vest						4 years
Ratio of number of shares into which the share instrument may be converted \| shares						1
Vesting period						4 years
Time-Based Restricted Stock Units (RSUs) [Member] \| 2010 Plan [Member]
Stockholders' Equity [Line Items]
Stock-based compensation						$ 4,900
Subsequent Event [Member] \| 2010 Plan [Member]
Stockholders' Equity [Line Items]
Additional common stock reserved for issuance \| shares		7,700,000
Subsequent Event [Member] \| 2010 Director Plan [Member]
Stockholders' Equity [Line Items]
Additional common stock reserved for issuance \| shares		1,500,000
Notes [Member]
Stockholders' Equity [Line Items]
Repayment of notes payable	$ 4,500			$ 4,500
Number of Notes holders paid \| item	1			1
Share-based Compensation Award, Tranche One, Two, Three and Four [Member] \| Time-Based Restricted Stock Units (RSUs) [Member]
Stockholders' Equity [Line Items]
Vesting percentage						25.00%

Segment And Geographic Information (Schedule of Revenue by Geographic Location) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 27,930	$ 21,915	$ 24,621	$ 16,425	$ 19,526	$ 18,160	$ 21,578	$ 19,362	$ 90,891	$ 78,626	$ 93,468
North America [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue									44,681	35,598	40,641
Europe (including the Middle East and Africa) [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue									19,600	13,958	14,026
Asia Pacific [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue									$ 26,610	$ 29,070	$ 38,801

Cash and Cash Equivalents and Investments

12 Months Ended

Dec. 31, 2019

Cash and Cash Equivalents and Investments [Abstract]

Cash and Cash Equivalents and Investments

NOTE 4. CASH AND CASH EQUIVALENTS AND INVESTMENTS

The following table summarizes our cash, cash equivalents and investments as of December 31, 2019 and 2018 (in thousands):



	As of December 31, 2019
			Gross		Gross
	Amortized		unrealized		unrealized		Fair
	Cost		gains		losses		Value
Cash and cash equivalents:
Cash and money market funds	$	18,644	$	—	$	—	$	18,644
Commercial paper		10,983		—		—		10,983
Total cash and cash equivalents		29,627		—		—		29,627
Investments:
Commercial paper		16,971		1		(1)		16,971
Corporate debt securities		2,496		5		—		2,501
Total investments		19,467		6		(1)		19,472
Total cash, cash equivalents and investments	$	49,094	$	6	$	(1)	$	49,099

Long-term restricted cash:
Cash	$	4,000	$	—	$	—	$	4,000

	As of December 31, 2018
			Gross		Gross
	Amortized		unrealized		unrealized		Fair
	Cost		gains		losses		Value
Cash and cash equivalents:
Cash and money market funds	$	18,844	$	—	$	—	$	18,844
Total cash and cash equivalents		18,844		—		—		18,844
Investments:
Commercial paper		53,493		—		(24)		53,469
Corporate debt securities		10,223		3		(12)		10,214
US government & agency securities		19,830		—		(3)		19,827
Total investments		83,546		3		(39)		83,510
Total cash, cash equivalents and investments	$	102,390	$	3	$	(39)	$	102,354

Long-term restricted cash:
Cash	$	4,500	$	—	$	—	$	4,500

The following table summarizes the contractual maturities of our cash equivalents and available-for-sale investments, excluding money market funds, as of December 31, 2019:



(in thousands)	Fair Value
Due in one year or less	$	30,455
Due after one year through five years		—
Total	$	30,455

Substantially all of our marketable debt investments are classified as current based on the nature of the investments and their availability for use in current operations.

Actual maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations without call or prepayment penalties.

Cash and Cash Equivalents and Investments (Summary of Contractual Maturities of Cash Equivalents and Available-for-Sale Investments) (Details) $ in Thousands	Dec. 31, 2019 USD ($)
Cash and Cash Equivalents and Investments [Abstract]
Due in one year or less	$ 30,455
Total investments	$ 30,455

Unaudited Selected Quarterly Financial Data (Schedule Of Unaudited Quarterly Financial Data) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Unaudited Selected Quarterly Financial Data [Abstract]
Total revenue	$ 27,930	$ 21,915	$ 24,621	$ 16,425	$ 19,526	$ 18,160	$ 21,578	$ 19,362	$ 90,891	$ 78,626	$ 93,468
Total gross profit	12,932	6,914	9,613	5,117	5,746	3,192	8,862	7,296	34,576	25,096	34,659
Total operating expenses	30,849	35,028	33,993	35,251	36,369	27,862	30,607	31,245	135,121	126,083	124,443
Loss from operations	(17,917)	(28,114)	(24,380)	(30,134)	(30,623)	(24,670)	(21,745)	(23,949)	(100,545)	(100,987)	(89,784)
Gain from Continuation Advances	18,000								18,000
Net loss	$ (91)	$ (29,123)	$ (24,596)	$ (30,324)	$ (30,799)	$ (25,044)	$ (22,540)	$ (24,179)	$ (84,134)	$ (102,562)	$ (92,189)
Basic and diluted net loss per share	$ 0.00	$ (0.19)	$ (0.16)	$ (0.20)	$ (0.21)	$ (0.19)	$ (0.17)	$ (0.20)
Weighted average shares used in computing net loss per share	153,051	152,983	152,776	151,274	149,314	135,130	131,882	123,768	152,527,000	135,094,000	105,682,000
Continuation Advances from Illumina	$ 18,000								$ 18,000

Unaudited Selected Quarterly Financial Data (Tables)

12 Months Ended

Dec. 31, 2019

Unaudited Selected Quarterly Financial Data [Abstract]

Schedule of Unaudited Quarterly Financial Data



	Fiscal 2019 Quarter Ended
(in thousands, except per share data)	March 31,		June 30,		September 30,		December 31,
Total revenue	$	16,425	$	24,621	$	21,915	$	27,930
Total gross profit		5,117		9,613		6,914		12,932
Total operating expenses		35,251		33,993		35,028		30,849
Loss from operations		(30,134)		(24,380)		(28,114)		(17,917)
Gain from Continuation Advances (1)		—		—		—		18,000
Net loss		(30,324)		(24,596)		(29,123)		(91)
Basic and diluted net loss per share	$	(0.20)	$	(0.16)	$	(0.19)	$	(0.0)
Weighted average shares used in computing net loss per share		151,274		152,776		152,983		153,051

	Fiscal 2018 Quarter Ended
(in thousands, except per share data)	March 31,		June 30,		September 30,		December 31,
Total revenue	$	19,362	$	21,578	$	18,160	$	19,526
Total gross profit		7,296		8,862		3,192		5,746
Total operating expenses		31,245		30,607		27,862		36,369
Loss from operations		(23,949)		(21,745)		(24,670)		(30,623)
Net loss		(24,179)		(22,540)		(25,044)		(30,799)
Basic and diluted net loss per share	$	(0.20)	$	(0.17)	$	(0.19)	$	(0.21)
Weighted average shares used in computing net loss per share		123,768		131,882		135,130		149,314

Notes Payable

12 Months Ended

Dec. 31, 2019

Notes Payable [Abstract]

Notes Payable

NOTE 6. NOTES PAYABLE

Facility Agreement

Under the terms of the Facility Agreement, we received $20.5 million and issued promissory notes in the aggregate principal amount of $20.5 million. The Notes bear simple interest at a rate of 8.75% per annum, payable quarterly in arrears commencing on April 1, 2013 and on the first business day of each January, April, July and October thereafter. The Facility Agreement has a maximum term of seven years. We received net proceeds of $20.0 million, representing $20.5 million of gross proceeds, less a $500,000 facility fee, before deducting other expenses of the transaction. On June 23, 2017, pursuant to a partial exercise by the Notes holders of their right to elect to receive up to 25% of the net proceeds from any financing that includes an equity component, we paid $4.5 million of outstanding principal, together with accrued and unpaid interest, to one of the Note holders with proceeds from our underwritten public equity offering. As of December 31, 2019, a balance of $16.0 million aggregate principal amount of debt remained outstanding under the Facility Agreement and presented as “Notes payable, current” on the consolidated balance sheet as of December 31, 2019

The Facility Agreement also contained various representations and warranties, and affirmative and negative covenants, customary for financings of this type, including restrictions on our ability to incur additional indebtedness or liens on our assets, except as permitted under the Facility Agreement. In addition, the Facility Agreement required us to maintain consolidated cash and cash equivalents on the last day of each calendar quarter of not less than $2.0 million. As security for our repayment of our obligations under the Facility Agreement, we granted the lenders a security interest in substantially all of our property and interests in property.

Subject to certain exceptions set forth in the Facility Agreement, holders representing a majority of the aggregate principal amount of the outstanding Notes issued pursuant to the Facility Agreement could elect to receive up to 25% of the net proceeds from any financing that includes an equity component. To the extent that we raise additional capital in the future through the sale of common stock, including without limitation, sales of common stock pursuant to an “at-the-market” offering program, we may be obligated, at the election of the holders of the Notes, to pay 25% of the net proceeds from any such financing activities as partial payment of the Notes.

In February 2020, we repaid the remaining outstanding principal of $16.0 million and interest to Deerfield and the Facility Agreement was terminated.

Financing Derivative

A number of features embedded in the Notes required accounting for as a derivative, including the indemnification of certain withholding taxes and the acceleration of debt upon (i) a qualified financing, (ii) an event of default, (iii) a Major Transaction (as such term is defined in the Facility Agreement), and (iv) the exercise of the warrant via offset to debt principal. These features represent a single derivative (the “Financing Derivative”) that was bifurcated from the debt instrument and accounted for as a liability at fair value, with changes in fair value between reporting periods recorded in other income (expense), net.

The estimated fair value of the Financing Derivative was determined by comparing the difference between the fair value of the Notes with and without the Financing Derivative by calculating the respective present values from future cash flows using a 6.5% and 9.6% weighted average market yield at December 31, 2019 and 2018, respectively. The estimated fair value of the Financing Derivative as of December 31, 2019 and 2018 were $0 and $16,000, respectively.

As of both December 31, 2019 and December 31, 2018, we had an outstanding principal amount of $16.0 million for the Notes, net of debt discount of $0.2 million and $1.3 million, respectively, resulting in a net $15.8 million and $14.7 million recorded as “Notes payable, current” and Notes payable, non-current” on the consolidated balance sheets as of December 31, 2019 and 2018, respectively, with repayment of all outstanding principal due in 2020.

In February 2020, we repaid the remaining outstanding principal of $16.0 million and interest to Deerfield and the debt agreement was terminated.

As of December 31, 2019, payments due under the Facility Agreement, which include interest and principal, are as follows:


	Amount
Years ending December 31,	(in thousands)
2020	$	16,491
Total remaining payments		16,491
Less: interest and discounts		(620)
Notes payable	$	15,871

Notes Payable (Schedule of Payments due under Notes Payabe) (Details) $ in Thousands	Dec. 31, 2019 USD ($)
Notes Payable [Abstract]
2020	$ 16,491
Total remaining payments	16,491
Less: interest and discounts	(620)
Notes payable	$ 15,871