GenMark Diagnostics (GNMK) 10-K 25 Feb 19 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Feb. 23, 2019	Jun. 30, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	GenMark Diagnostics, Inc.
Entity Central Index Key	1,487,371
Document Type	10-K
Document Period End Date	Dec. 31, 2018
Amendment Flag	false
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Well-known Seasoned Issuer	No
Entity Common Stock, Shares Outstanding		55,166,687
Entity Public Float			$ 334,644,000

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Current assets
Cash and cash equivalents	$ 36,286,000	$ 26,754,000
Short-term marketable securities	8,882,000	45,236,000
Accounts receivable, net of allowances of $75 and $2,754, respectively	11,534,000	10,676,000
Inventories	10,244,000	10,949,000
Prepaid expenses and other current assets	1,483,000	2,216,000
Total current assets	68,429,000	95,831,000
Property and equipment, net	21,070,000	22,581,000
Intangible assets, net	2,023,000	2,624,000
Restricted cash	758,000	758,000
Other long-term assets	701,000	505,000
Total assets	92,981,000	122,299,000
Current liabilities
Accounts payable	9,886,000	11,171,000
Accrued compensation	7,358,000	5,419,000
Current portion of long-term debt	0	7,927,000
Other current liabilities	3,043,000	3,226,000
Total current liabilities	20,287,000	27,743,000
Long-term liabilities
Deferred rent	2,996,000	3,059,000
Long-term debt	36,042,000	20,099,000
Other noncurrent liabilities	109,000	241,000
Total liabilities	59,434,000	51,142,000
Commitments and contingencies - See Note 7
Stockholders' equity
Preferred stock, $0.0001 par value; 5,000 authorized, none issued	0	0
Common stock, $0.0001 par value; 100,000 authorized; 56,240 and 55,066 shares issued and outstanding, respectively	6,000	6,000
Additional paid-in capital	500,344,000	487,525,000
Accumulated deficit	(466,883,000)	(416,383,000)
Accumulated other comprehensive income	80,000	9,000
Total stockholders’ equity	33,547,000	71,157,000
Total liabilities and stockholders’ equity	$ 92,981,000	$ 122,299,000

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Accounts receivable - net of allowance	$ 75	$ 2,754
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, authorized	5,000,000	5,000,000
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, authorized	100,000,000	100,000,000
Common stock, issued	56,240,000	55,066,000
Common stock, outstanding	56,240,000	55,066,000

CONSOLIDATED STATEMENT OF COMPR

CONSOLIDATED STATEMENT OF COMPREHENSIVE LOSS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue
Product revenue	$ 70,481	$ 52,260	$ 48,914
License and other revenue	278	259	360
Total revenue	70,759	52,519	49,274
Cost of revenue	51,278	32,514	19,700
Gross profit	19,481	20,005	29,574
Operating expenses:
Sales and marketing	21,777	20,557	14,734
General and administrative	17,545	16,205	14,363
Research and development	27,931	42,760	49,458
Total operating expenses	67,253	79,522	78,555
Loss from operations	(47,772)	(59,517)	(48,981)
Other income (expense):
Interest income	711	561	176
Interest expense	(3,108)	(3,042)	(1,536)
Other income (expense)	(192)	249	(160)
Total other income (expense)	(2,589)	(2,232)	(1,520)
Loss before provision for income taxes	(50,361)	(61,749)	(50,501)
Income tax expense	139	101	100
Net loss	$ (50,500)	$ (61,850)	$ (50,601)
Net loss per share, basic and diluted	$ (0.91)	$ (1.21)	$ (1.15)
Weighted average number of shares outstanding	55,669	51,169	44,100
Other comprehensive loss
Net loss	$ (50,500)	$ (61,850)	$ (50,601)
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	44	(84)	77
Net unrealized gains (losses) on marketable securities, net of tax	27	(2)	(11)
Other Comprehensive Income (Loss), Net of Tax	71	(86)	66
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ (50,429)	$ (61,936)	$ (50,535)

CONSOLIDATED STATEMENT OF STOCK

CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional paid-in capital	Accumulated other comprehensive loss	Accumulated deficit
Beginning balance at Dec. 31, 2015	$ 48,597	$ 4	$ 353,233	$ 29	$ (304,669)
Beginning Balance, Shares at Dec. 31, 2015		42,551
Issuance of stock in lieu of accrued bonuses	364	$ 0	364	0	0
Issuance of stock in lieu of accrued bonuses, Shares		28
Stock-based compensation expense	9,236	$ 0	9,236	0	0
Employee stock purchase plans, purchases	921	$ 0	921	0	0
Employee stock purchase plans, shares		138
Restricted stock awards issued, net of cancellations	0	$ 0	0	0	0
Restricted stock awards issued, net of cancellations, Shares		421
Shares issued under stock-based compensation plans, net of cancellations	712	$ 0	712	0	0
Shares issued under stock-based compensation plans, net of cancellations, Shares		99
Net loss	(50,601)	$ 0	0	0	(50,601)
Temporary Equity, Foreign Currency Translation Adjustments	77	0	0	77	0
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	77
Net unrealized gains (losses) on marketable securities, net of tax	(11)	0	0	(11)	0
Ending Balance at Dec. 31, 2016	38,151	$ 4	393,322	95	(355,270)
Ending Balance, Shares at Dec. 31, 2016		46,554
Stock-based compensation expense	12,170	$ 0	12,170	0	0
Employee stock purchase plans, purchases	1,016	$ 0	1,016	0	0
Employee stock purchase plans, shares		175
Restricted stock awards issued, net of cancellations	0	$ 0	0	0	0
Restricted stock awards issued, net of cancellations, Shares		955
Shares issued under stock-based compensation plans, net of cancellations	287	$ 0	287	0	0
Shares issued under stock-based compensation plans, net of cancellations, Shares		42
Issuance of common stock, net of offering expenses	80,732	$ 2	80,730	0	0
Issuance of common stock, net of offering expenses, Shares		7,340
Net loss	(61,850)	$ 0	0	0	(61,850)
Temporary Equity, Foreign Currency Translation Adjustments	(84)	0	0		0
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	(84)
Net unrealized gains (losses) on marketable securities, net of tax	(2)	0	0	(2)	0
Ending Balance at Dec. 31, 2017	71,157	$ 6	487,525	9	(416,383)
Ending Balance, Shares at Dec. 31, 2017		55,066
Stock-based compensation expense	11,697	$ 0	11,697	0	0
Employee stock purchase plans, purchases	1,061	$ 0	1,061	0	0
Employee stock purchase plans, shares		253
Restricted stock awards issued, net of cancellations	0	$ 0	0	0	0
Restricted stock awards issued, net of cancellations, Shares		916
Shares issued under stock-based compensation plans, net of cancellations	21	$ 0	21	0	0
Shares issued under stock-based compensation plans, net of cancellations, Shares		5
Net loss	(50,500)	$ 0	0	0	(50,500)
Temporary Equity, Foreign Currency Translation Adjustments	44	0	0		0
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	44
Net unrealized gains (losses) on marketable securities, net of tax	27	0	0	27	0
Ending Balance at Dec. 31, 2018	$ 33,547	$ 6	$ 500,344	$ 80	$ (466,883)
Ending Balance, Shares at Dec. 31, 2018		56,240

CONSOLIDATED STATEMENT OF CASH

CONSOLIDATED STATEMENT OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities
Net loss	$ (50,500)	$ (61,850)	$ (50,601)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	7,088	5,317	3,916
Net amortization/(accretion) of premiums/discounts on investments	(142)	(39)	89
Gain on sale of investment in preferred stock	0	0	(9)
Net amortization/(accretion) of premiums/discounts on investments	938	1,132	388
Stock-based compensation	11,697	12,170	9,236
Provision for Doubtful Accounts	23	14	13
Non-cash inventory adjustments	1,426	1,323	134
Other non-cash adjustments	15	(224)	145
Changes in operating assets and liabilities:
Accounts receivable	(878)	(1,555)	(2,250)
Inventories	(2,414)	(10,512)	(3,450)
Prepaid expenses and other assets	854	(599)	(613)
Accounts payable	(1,389)	2,557	4,105
Accrued compensation	1,059	(263)	2,172
Other current and non-current liabilities	(289)	(893)	1,088
Net cash used in operating activities	(32,512)	(53,422)	(35,637)
Investing activities:
Payments for intellectual property licenses	0	(500)	(1,500)
Purchases of property and equipment	(2,575)	(4,815)	(7,000)
Purchases of marketable securities	(29,778)	(70,989)	(33,688)
Proceeds from sales of marketable securities	0	13,896	8,015
Maturities of marketable securities	66,300	37,500	10,050
Net cash provided by (used in) investing activities	33,947	(24,908)	(24,123)
Financing activities:
Proceeds from issuance of common stock	1,061	87,267	30,920
Costs incurred in conjunction with public offering	0	(5,469)	(1,143)
Principal repayment of borrowings	92	7,848	40
Proceeds from borrowings	7,098	15,000	10,000
Costs associated with debt issuance	(20)	(187)	(90)
Proceeds from stock option exercises	22	287	712
Net cash provided by financing activities	8,069	89,050	40,359
Effect of exchange rate changes on cash	28	75	(25)
Net increase (decrease) in cash and cash equivalents	9,532	10,795	(19,426)
Cash and cash equivalents at beginning of year	27,512	16,717	36,143
Cash and cash equivalents at end of year	37,044	27,512	16,717
Non-cash investing and financing activities:
Transfer of systems from property and equipment into inventory	1,689	4,885	263
Property and equipment costs incurred but not paid included in accounts payable	372	227	1,159
Supplemental cash flow information:
Cash paid for interest	2,028	1,643	1,130
Cash paid for income taxes, net	$ 165	$ 61	$ 65

Organization and Basis of Prese

Organization and Basis of Presentation (Notes)	12 Months Ended
	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and basis of presentation	Organization and basis of presentation Organization GenMark Diagnostics, Inc., the Company or GenMark, was formed by Osmetech plc, or Osmetech, as a Delaware corporation in February 2010, and had no operations prior to its initial public offering, or the IPO, which was completed in June 2010. Immediately prior to the closing of the IPO, GenMark acquired all of the outstanding ordinary shares of Osmetech in a reorganization, accounted for in a manner similar to a pooling-of-interests, under the applicable laws of the United Kingdom. As a result of the reorganization, all of the issued ordinary shares in Osmetech were cancelled in consideration of (i) the issuance of common stock of GenMark to the former shareholders of Osmetech and (ii) the issuance of new shares in Osmetech to GenMark. Following the reorganization, Osmetech became a subsidiary controlled by GenMark, and the former shareholders of Osmetech received shares of GenMark. Any historical discussion of GenMark relates to Osmetech and its consolidated subsidiaries prior to the reorganization. In September 2012, GenMark placed Osmetech into liquidation to simplify its corporate structure. The liquidation of Osmetech was completed in the fourth quarter of 2013. The Company is a leading provider of multiplex molecular diagnostic solutions designed to enhance patient care, improve key quality metrics, and reduce the total cost-of-care. The Company offers a sample-to-answer ePlex instrument and associated molecular diagnostic panels. The Company's products also include the XT-8 instrument and related diagnostic and research tests, as well as certain custom manufactured reagents, collectively referred to as the XT-8 system. The Company sells its products in the U.S. and Europe directly and through distributors. Basis of Presentation and Principles of Consolidation The accompanying consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles, or U.S. GAAP, and applicable regulations of the U.S. Securities and Exchange Commission, or the SEC. The consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. The accompanying consolidated financial statements have been prepared on a going-concern basis, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business. The Company has incurred net losses from operations since its inception and has an accumulated deficit of $466,883,000 at December 31, 2018 . Management expects operating losses to continue through the foreseeable future. The Company's ability to transition to attaining profitable operations is dependent upon achieving a level of revenues adequate to support its cost structure through expanding its product offerings and consequently increasing its product revenues. Cash, cash equivalents, and marketable securities at December 31, 2018 totaled $45,168,000 . The Company has prepared cash flow forecasts which indicate, based on the Company’s current cash resources available, that the Company will have sufficient resources to fund its business for at least the next 12 months from the date of this filing. Segment Reporting The Company currently operates as one operating segment. Operating segments are defined as components of an enterprise for which separate financial information is evaluated regularly by the chief operating decision maker, who is the chief executive officer, in deciding how to allocate resources and assessing performance. The Company’s business operates in one operating segment because the Company’s chief operating decision maker evaluates the Company’s financial information and resources and assesses the performance of these resources on a consolidated basis. Since the Company operates in one operating segment, all required financial segment information can be found in the consolidated financial statements. Use of Estimates The preparation of these consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and the notes thereto. The Company’s significant estimates included in the preparation of the financial statements are related to accounts receivable, inventories, property and equipment, intangible assets, employee-related compensation accruals, warranty liabilities, tax valuation accounts and stock-based compensation. Actual results could differ from those estimates.

Summary of significant accounti

Summary of significant accounting policies (Notes)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Significant Accounting Policies [Text Block]	Summary of Significant Accounting Policies and Significant Accounts Cash and Cash Equivalents and Marketable Securities Cash and cash equivalents consist of cash on deposit with banks, money market instruments, and certificates of deposit with original maturities of three months or less at the date of purchase. Marketable securities consist of certificates of deposits that mature in greater than three months . Marketable securities are accounted for as "available-for-sale" with the carrying amounts reported in the balance sheets stated at cost, which approximates their fair market value, with unrealized gains and losses, if any, reported as a separate component of stockholders' equity and included in comprehensive loss. Restricted Cash Restricted cash represents amounts designated for uses other than current operations and includes $758,000 as of December 31, 2018 held as security for the Company’s letter of credit with Banc of California. Fair Value of Financial Instruments The Company uses a fair value hierarchy with three levels of inputs, of which the first two are considered observable and the last unobservable, to measure fair value: • 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 for similar assets or liabilities; quoted prices 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. • 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. The carrying amounts of financial instruments such as accounts receivable, prepaid expenses and other current assets, accounts payable, and accrued liabilities approximate the related fair values due to the short-term maturities of these instruments. Receivables Accounts receivable consist of amounts due to the Company for sales to customers and are recorded net of an allowance for doubtful accounts. The allowance for doubtful accounts is determined based on an assessment of the collectability of specific customer accounts, the aging of accounts receivable, and a reserve for unknown items based upon the Company’s historical experience. The allowance for doubtful accounts as of December 31, 2018 and 2017 , comprised the following (in thousands): Allowance for doubtful accounts Balance at December 31, 2016 $ 2,740 Provision for doubtful accounts 14 Balance at December 31, 2017 $ 2,754 Provision for doubtful accounts 23 Write off of uncollectible accounts (2,702 ) Balance at December 31, 2018 $ 75 The Company included $2,702,000 in the allowance for doubtful accounts as of December 31, 2017 and 2016 for past due amounts from its former customer, Natural Molecular Testing Corporation (NMTC). The fully reserved amounts due from NMTC were written off during the year ended December 31, 2018 . Inventories Inventories are stated at the lower of cost (first-in, first-out) or net realizable value and include direct labor, materials, and manufacturing overhead. The Company periodically reviews inventory for evidence of slow-moving or obsolete parts, and writes inventory down to net realizable value, as needed. This write-down is based on management’s review of inventories on hand, compared to estimated future usage and sales, shelf-life assumptions, and assumptions about the likelihood of obsolescence. If actual market conditions are less favorable than those projected by the Company, additional inventory write-downs may be required. Inventory impairment charges establish a new cost basis for inventory and charges are not reversed subsequently to income, even if circumstances later suggest that increased carrying amounts are recoverable. Property and Equipment, net Property, equipment and leasehold improvements are recorded at cost and depreciated using the straight-line method over the estimated useful lives of the assets, which are: Plant and Machinery 3 – 5 years Instruments 4 – 5 years Office equipment 3 – 7 years Leasehold improvements over the shorter of the remaining life of the lease or the useful economic life of the asset Property and equipment includes diagnostic instruments used for sales demonstrations or placed with customers under several types of arrangements, including performance evaluation programs, or PEPs, and reagent rental agreements. Instruments are placed with customers under PEPs for limited evaluation periods. Instruments are also placed with customers under reagent rental agreements, which generally require customers to purchase a minimum number of test cartridges over the term of the agreement. The Company retains title to the instrument under these arrangements. Maintenance and repair costs are expensed as incurred. Leased property meeting certain capital lease criteria is capitalized, and the net present value of the related lease payments is recorded as a liability. Amortization for assets noted as capital leases is recorded using the straight-line method over the shorter of the estimated useful lives or the lease terms. Intangible Assets Intangible assets are comprised of licenses or sublicenses to technology covered by patents owned by third parties, and are amortized on a straight-line basis over the expected useful lives of these assets, which is generally 10 years. Amortization of licenses typically begins upon the Company obtaining access to the licensed technology and is recorded in cost of revenues for licenses supporting commercialized products. The amortization of licenses to technology supporting products in development is recorded in research and development expenses. Impairment of Long-Lived Assets The Company assesses the recoverability of long-lived assets, including intangible assets, by periodically evaluating the carrying value whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. If impairment is indicated, the Company writes down the carrying value of the asset to its estimated fair value. This fair value is primarily determined based on estimated discounted cash flows. The Company did not recognize any impairment charges during the years ended December 31, 2018 , 2017 , and 2016 . Revenue Recognition The Company recognizes revenue from operations through the sale of products and other services. Product revenue is comprised of the sale of consumables and instruments. Revenue is recognized when control of products and services is transferred to the customer in an amount that reflects the consideration that the Company expects to receive from the customer in exchange for those products and services. This process involves identifying the contract with the customer, determining the performance obligations in the contract, determining the contract price, allocating the contract price to the distinct performance obligations in the contract, and recognizing revenue when the performance obligations have been satisfied. A performance obligation is considered distinct from other obligations in a contract when it provides a benefit to the customer either on its own or together with other resources that are readily available to the customer and is separately identified in the contract. The Company considers a performance obligation satisfied once it has transferred control of a good or service to the customer, meaning the customer has the ability to use and obtain the benefit of the good or service. The Company recognizes revenue for satisfied performance obligations only when it determines there are no uncertainties regarding payment terms or transfer of control. Revenue from product sales is recognized generally upon shipment to the end customer, which is when control of the product is deemed to be transferred. Invoicing typically occurs upon shipment and the term between invoicing and when payment is due is not significant. Revenue from instrument services is recognized as the services are rendered, typically evenly over the contract term. Revenue is recorded net of discounts, and sales taxes collected on behalf of governmental authorities. Employee sales commissions are recorded as selling and marketing expenses when incurred or amortized over the estimated contract term when resulting from new contract acquisition efforts. The Company allocates the contract price to each performance obligation in proportion to its stand-alone selling price. The stand-alone selling price is determined by the Company's best estimate of stand-alone selling price using average selling prices over a rolling 12-month period along with a specific assessment of any unique circumstances of the contract. For those products for which there is limited sales history, the Company makes price determinations based on similar product sales data. The following table presents disaggregated revenue by source (in thousands): Year ended December 31, 2018 2017 2016 Revenue Source: ePlex product revenue $ 37,901 $ 10,172 $ 1,478 XT-8 product revenue 32,580 42,088 47,436 Total product revenue 70,481 52,260 48,914 License and other revenue 278 259 360 Total revenue $ 70,759 $ 52,519 $ 49,274 In the years ended December 31, 2018 , 2017 and 2016 , Laboratory Corporation of America, Inc. represented 16% , 20% , and 27% , respectively, of the Company's total revenue. The Company incurs incremental costs to obtain customer contracts including commissions and bonuses. The Company capitalizes the incremental costs to obtain customer contracts, which are amortized using the straight-line method over the contract term. The Company reported capitalized contract acquisition costs of $1,055,000 as of December 31, 2018 and amortization expense of $567,000 for the year ended December 31, 2018 . Product Warranties The Company generally offers a one -year warranty for its instruments sold to customers and up to a sixty -day warranty for reagents and provides for the estimated cost of the product warranty at the time the system sale is recognized. Factors that affect the Company’s warranty reserves include the number of units sold, historical and anticipated rates of warranty repairs and the cost per warranty repair. The Company periodically assesses and if necessary adjusts the adequacy of the warranty reserve. Product warranty reserve activity for the years ended December 31, 2018 , 2017 and 2016 is as follows (in thousands): 2018 2017 2016 Beginning balance $ 470 $ 219 $ 118 Warranty expenses incurred (1,495 ) (1,160 ) (421 ) Provisions 1,355 1,411 522 Ending balance $ 330 $ 470 $ 219 Research and Development Costs The Company expenses all research and development costs in the periods in which they are incurred unless there is alternative future use that supports the capitalization of an asset. Income Taxes Current income tax expense is the amount of income taxes expected to be payable for the current year. A deferred income tax liability or asset is established for the expected future tax consequences resulting from the differences in financial reporting and tax bases of assets and liabilities. A valuation allowance is provided if it is more likely than not that some or all of the deferred tax assets will not be realized. A full valuation allowance has been recorded against the Company’s net deferred tax assets due to the uncertainty surrounding the Company’s ability to utilize these assets in the future. The Company provides for uncertain tax positions when such tax positions do not meet the recognition thresholds or measurement standards prescribed by the authoritative guidance on income taxes. Amounts for uncertain tax positions are adjusted in periods when new information becomes available or when positions are effectively settled. The Company recognizes accrued interest related to uncertain tax positions as a component of income tax expense. A tax position that is more likely than not to be realized is measured at the largest amount of tax benefit that is greater than 50% likely of being realized upon settlement with the taxing authority that has full knowledge of all relevant information. Measurement of a tax position that meets the more likely than not threshold considers the amounts and probabilities of the outcomes that could be realized upon settlement using the facts, circumstances and information available at the reporting date. Stock-Based Compensation The Company recognizes stock-based compensation expense related to stock options, shares purchased under the Company's 2013 Employee Stock Purchase Plan, or ESPP, restricted stock awards, restricted stock units, and market-based stock units granted to employees and directors in exchange for services. The compensation expense is based on the fair value of the applicable award utilizing various assumptions regarding the underlying attributes of the award. The stock-based compensation expense is recorded in cost of revenues, sales and marketing, research and development, and/or general and administrative expenses based on the employee's respective function. The estimated fair value of stock granted, net of forfeitures expected to occur during the vesting period, is amortized as compensation expense that approximates straight-line expense to reflect vesting as it occurs. The stock option expense is derived from the Black-Scholes option pricing model that uses several judgment-based variables to calculate the expense. The market-based stock expense is derived from the Monte Carlo Simulation Valuation. The inputs utilized in the valuation of the stock-based awards include the following factors: • Expected Term. Expected term represents the period that the stock-based awards are expected to be outstanding and is determined by using the simplified method. • Expected Volatility . Expected volatility represents the expected volatility in the Company’s stock price over the expected term of the option or market-based award and is determined by review of the Company’s and similar companies’ historical experience. • Expected Dividend . The valuation methods requires a single expected dividend yield as an input. The Company assumed no dividends as it has never paid dividends and has no current plans to do so. • Risk-Free Interest Rate. The risk-free interest rate is based on published U.S. Treasury rates in effect at the time of grant for periods corresponding with the expected term of the option or market-based award. The compensation expense related to the grant of restricted stock awards or units is calculated as the fair market value of the stock on the grant date as further adjusted to reflect expected forfeitures. Foreign Currency Translation The Company translates the assets and liabilities of the Company's entities outside the U.S. into U.S. Dollars based on the foreign currency exchange rates at the end of each period. Gains or losses resulting from these foreign currency translations are recorded in accumulated comprehensive loss in the consolidated statement of stockholders' equity. Foreign currency translation impacts recorded in accumulated other comprehensive loss (gain) for the years ended December 31, 2018 , 2017 , and 2016 were $44,000 , $(84,000) , and $77,000 , respectively. Revenue and expenses are translated at weighted average exchange rates during the applicable period. Transactions in foreign currencies were recognized using the rate of exchange prevailing at the date of the transaction. Foreign exchange gains (losses), which are included in the accompanying consolidated statements of operations, totaled $(196,000) , $225,000 , and $169,000 for the years ended December 31, 2018 , 2017 and 2016 , respectively, and relate primarily to transactions denominated in Euros. Net Loss per Common Share Basic net loss per share is calculated by dividing loss available to stockholders of our common stock (the numerator) by the weighted average number of shares of the Company's common stock outstanding during the period (the denominator). Shares issued during the period and shares reacquired during the period are weighted for the portion of the period that they were outstanding. Diluted loss per share is calculated in a similar way to basic loss per share except that the denominator is increased to include the number of additional shares that would have been outstanding if the dilutive potential shares had been issued unless the effect would be anti-dilutive. The calculations of diluted net loss per share for the years ended December 31, 2018 , 2017 and 2016 did not include the effects of the following stock options or other unvested equity awards which were outstanding as of the end of each year because the inclusion of these securities would have been anti-dilutive (in thousands). Year Ended December 31, 2018 2017 2016 Options outstanding to purchase common stock 2,440 2,490 2,570 Other unvested equity awards 2,994 2,307 2,000 Total 5,434 4,797 4,570 Concentration of Risk Financial instruments which potentially subject us to concentrations of credit risk consist primarily of cash, cash equivalents, short-term investment securities, and accounts receivable. We limit our exposure to credit loss by placing our cash with high credit quality financial institutions. We have established guidelines relative to diversification of our cash and investment securities and their maturities that are intended to secure safety and liquidity. The following table summarizes customers who accounted for 10% or more of net accounts receivable: December 31, 2018 2017 Laboratory Corporation of America, Inc. 24 % 23 % Comprehensive Loss The Company has the option to present the total of comprehensive income, the components of net income, and the components of other comprehensive income either in a single continuous statement of comprehensive income or in two separate but consecutive statements. The Company’s comprehensive loss comprises net losses, unrealized gains and losses on available for sale securities, and foreign currency translation. Recent Accounting Pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board, or FASB, or other standard setting bodies that the Company adopts as of the specified effective date. In June 2018, the FASB issued Accounting Standards Update, or ASU 2018-07, Compensation - Stock Compensation (Topic 718), which simplifies the accounting for non-employee share-based payment transactions. The new standard expands the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from non-employees. ASU 2018-07 is effective for fiscal years beginning after December 15, 2018 (including interim periods within that fiscal year), with early adoption permitted. The Company adopted the new standard in the second quarter of 2018 and determined that the application of the new standard did not have a material impact on the Company's consolidated financial statements. In November 2016, the FASB issued ASU, 2016-18, Statement of Cash Flows (Topic 230) Restricted Cash, which requires amounts generally described as restricted cash and restricted cash equivalents to be included in the cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. ASU 2016-18 is effective for fiscal years beginning after December 15, 2017 (including interim periods within those periods) using a retrospective transition method for each period presented, with early adoption permitted. The Company adopted the new standard in the first quarter of 2018 using the retrospective transition method resulting in an increase in the beginning and ending cash balance of $758,000 . In February 2016, the FASB issued ASU 2016-02, Leases, which outlines a comprehensive lease accounting model and supersedes the current lease guidance. The new guidance requires lessees to recognize lease liabilities and corresponding right‑of‑use assets for all leases with lease terms of greater than 12 months. It also changes the definition of a lease and expands the disclosure requirements of lease arrangements. The new guidance must be adopted using the modified retrospective approach and will be effective for the Company starting in the first quarter of 2019, with early adoption permitted. The Company will adopt ASU 2016-02 beginning on January 1, 2019 and will recognize an operating lease liability and operating right-of-use asset in its consolidated balance sheet. The standard will not have a material impact on the Company's finance leases. The Company will no longer present deferred rent in its consolidated balance sheet as it is considered a component of the operating right-of-use asset. The Company will add additional disclosures to its consolidated financial statements surrounding the remaining term and discount rate of its operating leases. In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606), an updated standard on revenue recognition. The new standard provides enhancements to the quality and consistency of how revenue is reported under the principle that revenue should be recognized in an amount that reflects the consideration to which the Company expects to be entitled in exchange for the transfer of promised goods or services. The Company adopted the new standard using the modified retrospective transition method. The cumulative effect of applying the new standard as of January 1, 2018 resulted in a net increase in opening retained earnings of $737,000 to capitalize certain costs to obtain sales contracts. The Company recognized $567,000 in expense related to the amortization of capitalized contract costs during the year ended December 31, 2018 . Aside from this adjustment to beginning retained earnings and the related amortization of expense during the year ended December 31, 2018 , the application of this standard did not have a material impact on the Company's consolidated financial statements as of and for the year ended December 31, 2018 .

Intangible Assets, net

Intangible Assets, net	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets, net	Intangible Assets, net Intangible assets as of December 31, 2018 and 2017 comprised the following (in thousands): December 31, 2018 December 31, 2017 Gross carrying amount Accumulated amortization Net carrying amount Gross carrying amount Accumulated amortization Net carrying amount Licensed intellectual property $ 4,750 $ (2,727 ) $ 2,023 $ 4,750 $ (2,126 ) $ 2,624 In July 2012, the Company entered into a development collaboration and license agreement with Advanced Liquid Logic, Inc., or ALL, which was acquired by Illumina, Inc. in July 2013. Under the terms of the agreement, the Company established a collaborative program to develop in-vitro diagnostic products incorporating ALL’s proprietary electrowetting technology in conjunction with the Company’s electrochemical detection technology. The Company paid ALL an upfront license payment of $250,000 and agreed to pay up to $1,750,000 in potential additional milestone payments. In June 2017, the Company satisfied the final commercial milestone under this agreement requiring the payment of $500,000 , which was recorded as licensed intellectual property. Intellectual property licenses had a weighted average remaining amortization period of 3.43 years as of December 31, 2018 . Amortization expense for intangible assets amounted to $601,000 , $546,000 , and $406,000 for the years ended December 31, 2018 , 2017 and 2016 , respectively. Estimated future amortization expense for these licenses is as follows (in thousands): Years Ending December 31, Future Amortization Expense 2019 $ 591 2020 591 2021 591 2022 250 Total $ 2,023

Stockholders' Equity (Notes)

Stockholders' Equity (Notes)	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Stockholders' Equity	Stockholders’ Equity On June 13, 2017, the Company entered into an Underwriting Agreement, or the Underwriting Agreement, with J.P. Morgan Securities LLC and Merrill Lynch, Pierce, Fenner & Smith Incorporated acting as joint book-running managers and as representatives of the underwriters, or the Underwriters, relating to the issuance and sale of 6,382,978 shares of the Company's common stock, or the Offering. The price to the public in the Underwriting Agreement was $11.75 per share, before underwriting discounts and commissions. Under the terms of the Underwriting Agreement, the Company granted the Underwriters an option, exercisable for 30 days, to purchase up to an additional 957,446 shares of common stock pursuant to the Offering. The Offering was completed on June 19, 2017, pursuant to which the Company sold a total of 7,340,424 shares of its common stock for gross proceeds of $86,250,000 . The Company incurred $5,520,000 in related transaction costs, comprising underwriting discounts and commissions of $5,175,000 paid in accordance with the Underwriting Agreement, and approximately $345,000 in additional miscellaneous offering expenses. In June 2016, the Company entered into an Equity Distribution Agreement, or the Distribution Agreement, with Canaccord Genuity Inc., as sales agent, or Canaccord, pursuant to which the Company could, at its discretion, offer and sell, from time to time, through Canaccord shares of its common stock having an aggregate offering price of up to $30,000,000 . Under the Distribution Agreement, Canaccord could sell shares by any method deemed to be an “at-the-market” offering as defined in Rule 415 under the Securities Act or any other method permitted by law, including in privately negotiated transactions. The Company began sales under the Distribution Agreement in August 2016 pursuant to an effective shelf registration statement on Form S-3 previously filed with the SEC. During the three months ended September 30, 2016, the Company sold 3.3 million shares of common stock, at an average per share price of $9.04 , for aggregate gross proceeds of $30,000,000 . The Company incurred $1,143,000 in related transaction costs, comprising commissions paid to Canaccord of 3.0% of the aggregate gross proceeds from each sale of shares occurring pursuant to the Distribution Agreement, or $900,000 , and $243,000 in additional miscellaneous expenses.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock Based Compensation	Stock-Based Compensation In 2010, the Company adopted the 2010 Equity Incentive Plan, or the 2010 Plan, which provides for the grant of incentive and nonstatutory stock options, restricted stock, stock appreciation rights, restricted stock units, restricted stock bonuses and other stock-based awards. Employee participation in the 2010 Plan is at the discretion of the Compensation Committee of the Board of Directors of the Company. As of December 31, 2018 , there were 539,902 shares available for future grant of awards under the 2010 Plan. The Company estimates potential forfeitures of stock-based award grants and adjusts compensation cost recorded accordingly. The estimate of forfeitures is based on historical forfeiture experience and is adjusted over the requisite service period to the extent that actual forfeitures differ, or are expected to differ, from such estimates. Changes in estimated forfeitures will be recognized through a cumulative catch-up adjustment in the period of evaluation and will also impact the amount of stock compensation expense to be recognized in future periods. Stock Options All stock options granted under the 2010 Plan are exercisable at a price equal to the closing quoted market price of the Company’s shares on the NASDAQ Global Market on the date of grant and vest over a period of 4 years . Stock options are generally exercisable for a period up to 10 years after grant and are forfeited if employment is terminated before the options vest. The following table summarizes stock option activity during the year ended December 31, 2018 : Number of shares Weighted average exercise price Outstanding at December 31, 2017 2,490,465 $ 9.59 Granted — $ — Exercised (5,042 ) $ 4.33 Canceled (45,509 ) $ 11.35 Outstanding at December 31, 2018 2,439,914 $ 9.57 Vested and expected to vest at December 31, 2018 2,439,607 $ 9.57 Exercisable at December 31, 2018 2,416,389 $ 9.54 No stock options were granted in the years ended December 31, 2018 and 2017. Stock options that were exercisable as of December 31, 2018 had a remaining weighted average contractual term of 3.82 years and an aggregate intrinsic value of $290,000 . As of December 31, 2018 , there was $75,000 of unrecognized compensation cost related to stock options, which is expected to be recognized over a weighted average period of 0.16 years. The intrinsic value of stock options exercised during the years ended December 31, 2018 , 2017 and 2016 was $6,700 , $173,000 and $184,000 , respectively. As of December 31, 2018 , there were 2,439,914 stock options outstanding, which had a remaining weighted average contractual term of 3.84 years and an aggregate intrinsic value of $290,300 . The Company uses the Black-Scholes option pricing model to estimate the fair value on the applicable grant date. The assumptions used in the valuation of stock options granted in the years ended December 31, 2018 , 2017 and 2016 , are summarized in the following table: Years Ended December 31, 2018 2017 2016 Expected volatility — % — % 51 % Expected life (years) — — 5.90 Risk free rate — % — % 1.35 % Expected dividend yield — % — % — % Restricted Stock Awards and Units In March 2013, the Company transitioned to granting restricted stock units under the 2010 Plan in lieu of granting restricted stock awards. The remaining restricted stock awards vested during the year ended December 31, 2017 and all remaining expense for restricted stock awards granted by the Company was recognized during the year ended December 31, 2017. Restricted stock awards or units may be granted at the discretion of the Compensation Committee of the Board of Directors under the 2010 Plan in connection with the hiring or retention of personnel and are subject to certain conditions. Restrictions expire after the grant date in accordance with specific provisions in the applicable award agreement. The Company’s restricted stock unit activity for the year ended December 31, 2018 was as follows: Restricted Stock Units Number of shares Weighted Average Grant Date Fair Value Unvested at December 31, 2017 2,073,440 $ 9.14 Granted 1,827,626 $ 4.55 Vested (953,156 ) $ 9.30 Canceled (282,202 ) $ 7.33 Unvested at December 31, 2018 2,665,708 $ 6.12 As of December 31, 2018 , there was $11,098,000 of unrecognized compensation cost related to restricted stock units, which is expected to be recognized over a weighted average period of 2.46 years. The total fair value of restricted stock units that vested during the years ended December 31, 2018 , 2017 and 2016 was $5,404,000 , $7,813,000 and $3,192,000 , respectively. Market-Based and Performance Stock Units The Company issued market-based stock units in February 2018, 2017 and 2016, which may result in the recipient receiving shares of stock equal to up to 200% of the target number of units granted. The vesting and issuance of Company stock subject to the market-based stock units depends on the Company's stock performance as compared to the NASDAQ Composite Index over the three -year period following the grant. As of December 31, 2018 , there was $1,283,000 of unrecognized stock-based compensation expense related to these awards, which is expected to be recognized over a weighted average period of 1.58 years. The total fair value of market-stock units that vested during the years ended December 31, 2018 , 2017 , and 2016 was $645,000 , $0 , and $2,433,000 , respectively. The Company’s market-based stock unit activity for the year ended December 31, 2018 was as follows: Market-Based Stock Units Number of Shares Weighted Average Grant Date Fair Value Unvested at December 31, 2017 233,743 $ 10.88 Units granted 320,000 $ 7.19 Vested (108,320 ) $ 7.19 Canceled (116,684 ) $ 6.58 Unvested at December 31, 2018 328,739 $ 10.03 The fair value of these market-based stock units was estimated on the date of grant using the Monte Carlo Simulation Valuation Model, which estimates the potential outcome of achieving the market condition based on simulated future stock prices, with the following assumptions: Years Ended December 31, 2018 2017 2016 Expected volatility 65 % 54 % 49 % Risk-free interest rate 2.40 % 1.50 % 0.90 % Expected dividend — % — % — % Weighted average fair value $ 7.19 $ 13.82 $ 4.94 The Company granted 43,200 performance-based restricted stock units in March 2014 with a grant date fair value of $12.30 per share. The vesting and issuance of Company stock pursuant to these awards depended on obtaining regulatory clearance of a designated number of ePlex products within a defined time. Stock-based compensation expense for performance-based awards is recognized when it is probable that the applicable performance criteria will be satisfied. The probability of achieving the relevant performance criteria is evaluated on a quarterly basis. On December 31, 2014, 10,800 shares of Company stock were earned and vested pursuant to outstanding performance-based restricted stock units with a total fair value of $147,000 . On each of December 31, 2017, 2016, and 2015, 10,800 units were forfeited and canceled as the related performance metrics were not achieved by such dates. No performance-based restricted stock units were outstanding as of December 31, 2017 and all compensation related to the performance-based restricted stock units had been recognized. Employee Stock Purchase Plan The Company's stockholders originally approved the ESPP in May 2013 at the Company's Annual Meeting of Stockholders. In May 2018, the Company's stockholders approved the amendment and restatement of the ESPP, which increased the shares authorized for issuance under the ESPP from 650,000 to 1,750,000 . The price at which stock is purchased under the ESPP is equal to 85% of the fair market value of the common stock on the first or the last day of the offering period, whichever is lower. Generally, each offering under the ESPP will be for a period of six months as determined by the Company's board of directors; provided that no offering period may exceed 27 months . Employees may invest up to 10% of their gross compensation through payroll deductions. In no event may an employee purchase more than 1,500 shares of common stock during any six-month offering period. As of December 31, 2018 , there were 940,493 shares of common stock available for issuance under the ESPP. The ESPP is a compensatory plan as defined by the authoritative guidance for stock compensation. As a result, stock-based compensation expense related to the ESPP has been recorded during the year ended December 31, 2018 . A summary of ESPP activity for the years ended December 31, 2018 , 2017 , and 2016 is as follows (in thousands, except share and per share data): Years Ended December 31, 2018 2017 2016 Shares issued 252,623 174,723 138,058 Weighted average fair value of shares issued $ 4.20 $ 5.82 $ 6.67 Employee purchases $ 1,061 $ 1,016 $ 921 The Company uses the Black-Scholes model to estimate the fair value on the date of grant for ESPP purchase rights. The assumptions used in the valuation for the years ended December 31, 2018 , 2017 and 2016 , are summarized in the following table: Years Ended December 31, 2018 2017 2016 Expected volatility 73% - 54% 90% - 36% 69% - 52% Expected life (years) 0.50 0.50 0.50 Risk free rate 2.6% - 2.1% 1.5% - 0.6% 0.6% - 0.4% Expected dividend yield — % — % — % Stock-Based Compensation Expense Recognition Stock-based compensation was recognized in the consolidated statements of comprehensive loss as follows (in thousands): Years Ended December 31, 2018 2017 2016 Cost of revenue $ 871 $ 546 $ 258 Sales and marketing 5,549 2,819 2,329 Research and development 2,470 3,039 2,482 General and administrative 2,807 5,766 4,167 Total stock-based compensation expense $ 11,697 $ 12,170 $ 9,236 No stock-based compensation was capitalized during the periods presented, and there was no unrecognized tax benefit related to stock-based compensation for the years ended December 31, 2018 , 2017 and 2016 , respectively.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company's income (loss) before provision (benefit) for income taxes for the years ended December 31, 2018 , 2017 , and 2016 , respectively, was generated in the following jurisdictions (in thousands): Years Ended December 31, 2018 2017 2016 Domestic $ (50,938 ) $ (62,495 ) $ (50,651 ) Foreign 577 746 150 Total loss before income taxes $ (50,361 ) $ (61,749 ) $ (50,501 ) The components of income tax expense (benefit) were as follows for the years ended December 31, 2018 , 2017 , and 2016 , respectively (in thousands): Years Ended December 31, 2018 2017 2016 Current expense (benefit): U.S. Federal $ 4 $ (1 ) $ 11 State 43 22 35 Foreign 99 80 51 Total current expense 146 101 97 Deferred expense (benefit): U.S. Federal (5 ) — 2 State (2 ) — 1 Total deferred expense (7 ) — 3 Provision for income taxes $ 139 $ 101 $ 100 The components of net deferred income taxes consisted of the following at December 31, 2018 and 2017 , respectively (in thousands): As of December 31, 2018 2017 Deferred income tax assets: NOL and credit carryforwards $ 75,063 $ 64,486 Compensation accruals 4,542 4,143 Accruals and reserves 1,401 2,207 State tax provision 7 5 Inventory adjustments 1,193 1,329 Intangible assets 498 455 Other 620 65 Gross deferred tax assets 83,324 72,690 Less: valuation allowance (81,964 ) (71,464 ) Total deferred tax assets 1,360 1,226 Deferred income tax liabilities: Depreciation 1,102 1,226 Contract acquisition costs 258 — Total deferred tax liabilities 1,360 1,226 Net deferred tax assets (liabilities) $ — $ — A reconciliation of income tax expense to the amount computed by applying the statutory federal income tax rate to the loss from operations is summarized for the years ended December 31, 2018 , 2017 , and 2016 , respectively, as follows: Years Ended December 31, 2018 2017 2016 U.S. Federal statutory income tax rate 21.0 % 34.0 % 34.0 % Permanent differences (0.2 )% (0.2 )% (0.3 )% State taxes 3.0 % 2.8 % 2.3 % Executive compensation limitation (0.5 )% (0.5 )% (0.1 )% Tax reform 0.1 % (59.0 )% — % Stock-based compensation (2.6 )% 1.4 % (3.5 )% Other 0.1 % 0.2 % (0.4 )% Valuation allowance (21.2 )% 21.1 % (32.2 )% Total tax provision (0.3 )% (0.2 )% (0.2 )% The Company had federal net operating loss (NOL) carryforwards available of approximately $306,800,000 as of December 31, 2018 after consideration of limitations under Section 382 of the Internal Revenue Code, or Section 382, as further described below. The net loss generated in 2018 of $42,200,000 will carry forward indefinitely and be available to offset up to 80% of future taxable income each year. Additionally, the Company had state NOL carryforwards available of $215,000,000 as of December 31, 2018 . These federal and state NOLs may be used to offset future taxable income and will begin to expire in 2025 and 2019 , respectively. The Company adopted ASU 2016-09 in the first quarter of 2017. Under the new guidance, companies will no longer record excess tax benefits and certain tax deficiencies related to share-based payments to employees in additional paid-in capital. Instead, all income tax effects of awards will be recognized in the income statement when awards vest or are settled. All excess tax benefits not previously recognized were to be recorded to retained earnings as a cumulative effect adjustment upon adoption. Upon adoption, no adjustment to retained earnings was necessary due to the Company’s valuation allowance position. Approximately $1,976,000 attributable to excess tax benefits on stock compensation that had not been previously recognized was added to the deferred tax asset for NOLs with a corresponding increase to the valuation allowance. The future utilization of the Company’s NOL carryforwards to offset future taxable income may be subject to a substantial annual limitation as a result of changes in ownership by stockholders that hold 5% or more of the Company’s common stock . An assessment of such ownership changes under Section 382 was completed through December 31, 2018 . As a result of this assessment, the Company determined that it experienced multiple ownership changes through 2018 which will limit the future utilization of NOL carryforwards. The Company has reduced its deferred tax assets related to NOL carryovers that are anticipated to expire unused as a result of ownership changes. These tax attributes have been excluded from deferred tax assets with a corresponding reduction of the valuation allowance with no net effect on income tax expense or the effective tax rate. Additionally, future ownership changes may further impact the utilization of existing NOLs. The Company has established a full valuation allowance for its deferred tax assets due to uncertainties that preclude it from determining that it is more likely than not that the Company will be able to generate sufficient taxable income to realize such assets. Management assesses the available positive and negative evidence to estimate if sufficient future taxable income will be generated to utilize the existing deferred tax assets. A significant piece of objective negative evidence evaluated was the cumulative loss incurred over the three year period ended December 31, 2018 . Such objective evidence limits the ability to consider other subjective evidence, such as the Company's projections for future growth. Based on this evaluation, as of December 31, 2018 , a valuation allowance of $81,964,000 has been recorded in order to measure only the portion of the deferred tax asset that more likely than not will be realized. The amount of the deferred tax asset considered realizable, however, could be adjusted if objective negative evidence in the form of cumulative losses is no longer present and additional weight may be given to subjective evidence, such as estimates of future taxable income during carryforward periods and the Company's projections for growth. The Tax Cuts and Jobs Act, or the Jobs Act, was enacted on December 22, 2017 and introduced significant changes to U.S. income tax law. Effective in 2018, the Jobs Act reduced the U.S. federal corporate tax rate from 34% to 21% , required companies to pay a one-time transition tax on earnings of certain foreign subsidiaries that were previously tax deferred, and created new taxes on certain foreign sourced earnings. Due to the timing of the enactment and the complexity involved in applying the provisions of the Jobs Act, the Company applied the guidance in SEC Staff Accounting Bulletin (SAB) 118 by making reasonable estimates of the effects of the Jobs Act and recording provisional amounts in the consolidated financial statements as of December 31, 2017, March 31, 2018, June 30, 2018, and September 30, 2018. We have completed our accounting for the tax effects of the Jobs Act and recorded adjustments to the provisional amounts previously recorded. As of December 31, 2017, the Company remeasured certain deferred tax assets and liabilities based on the rates at which they were expected to reverse in the future, by recording a provisional expense of $36,400,000 , which was fully offset by a corresponding decrease in the valuation allowance. Upon further analysis of certain aspects of the Jobs Act and refinement of our calculations during the year ended December 31, 2018, we determined that an adjustment of $(56,374) was necessary to our provisional amount for the remeasurement of deferred tax assets and liabilities, which was fully offset by a corresponding increase in the valuation allowance. The one-time transition tax is based on the total post-1986 earnings and profits (E&P) previously deferred from U.S. income taxes. In aggregate, the Company has a deficit in post-1986 E&P from its foreign subsidiaries resulting in no increase in income tax expense as a result of the transition tax. No amounts have been provided for any additional outside basis difference inherent in these entities, as these amounts continue to be indefinitely reinvested in foreign operations. The FASB Staff Q&A, Topic 740, No. 5, Accounting for Global Intangible Low-Taxed Income (GILTI), states that an entity can make an accounting policy election to either recognize deferred taxes for temporary basis differences expected to reverse as GILTI in future years or to provide for the tax expense related to GILTI in the year the tax is incurred as a period expense only. Because we were evaluating the provision of GILTI as of December 31, 2017, we recorded no GILTI-related deferred amounts in 2017. After further consideration in the current year, we have elected to account for GILTI in the year the tax is incurred. The Company applies the two-step approach to recognizing and measuring uncertain tax positions. The first step is to evaluate the tax position for recognition by determining if the weight of available evidence indicates it is more likely than not that the position will be sustained on audit, including resolution of related appeals or litigation processes, if any. The second step is to measure the tax benefit as the largest amount, which is more than 50% likely of being realized upon ultimate settlement. Income tax positions must meet a more likely than not recognition threshold at the effective date to be recognized upon the adoption of ASC 740 and in subsequent periods. This interpretation also provides guidance on measurement, derecognition, classification, interest and penalties, accounting in interim periods, disclosure and transition. There were no unrecognized tax benefits for the years ended December 31, 2018 , 2017 and 2016 . At December 31, 2018 and December 31, 2017 , the Company had not accrued any interest or penalties related to uncertain tax positions. The Company does not anticipate that there will be a significant change in the amount of unrecognized tax benefits over the next twelve months. The Company recognizes interest and penalties related to uncertain tax positions in income tax expense. The Company is subject to taxation in the United States and various state and foreign jurisdictions. The Company's Federal and state tax returns since inception are subject to examination due to the carryover of net operating losses. As of December 31, 2018 , the Company’s tax years from 2012 through 2013 are subject to examination by the United Kingdom tax authorities. The statute of limitations for the assessment and collection of income taxes related to other foreign tax returns varies by country. In the foreign countries where the Company has operations, these time periods generally range from three to five years after the year for which the tax return is due or the tax is assessed.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Leases The Company has lease agreements for its office, manufacturing, warehousing and laboratory space and for office equipment. Rent and operating expenses charged were $1,808,000 , $1,654,000 and $1,871,000 for the years ended December 31, 2018 , 2017 , and 2016 , respectively. Pursuant to the Company’s lease agreements, a portion of the monthly rent has been deferred. The balance deferred at December 31, 2018 and 2017 was $3,516,000 and $3,652,000 , respectively. In July 2018, the Company entered into an amendment to the existing lease for its corporate headquarters, which extended the term of the lease by an additional four years through June 2025 . Base rent adjusts periodically throughout the extended term of this lease with monthly lease payments ranging from $107,000 to $117,000 . In connection with entering into this lease amendment, the Company also received certain rent abatements during the year ended December 31, 2018 . Annual future minimum obligations for leases as of December 31, 2018 are as follows (in thousands): Years Ending December 31, Amount 2019 $ 1,989 2020 1,997 2021 2,015 2022 2,077 2023 1,939 Thereafter 2,084 Total minimum lease payments $ 12,101 Legal Proceedings From time to time, the Company is party to litigation and other legal proceedings in the ordinary course, and incidental to the conduct of its business. While the results of any litigation or other legal proceedings are uncertain, the Company does not believe the ultimate resolution of any pending legal matters is likely to have a material effect on its financial position or results of operations.

Inventories

Inventories	12 Months Ended
	Dec. 31, 2018
Inventory Disclosure [Abstract]
Inventories	Inventories Inventory on hand as of December 31, 2018 and 2017 comprised the following (in thousands): December 31, 2018 2017 Raw materials $ 2,449 $ 4,534 Work-in-process 3,349 3,638 Finished goods 4,446 2,777 Total inventory $ 10,244 $ 10,949

Property and Equipment, net

Property and Equipment, net	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment, Net [Abstract]
Property and Equipment, net	Property and Equipment, net Property and equipment comprised the following as of December 31, 2018 and 2017 (in thousands): December 31, 2018 2017 Property and equipment–at cost: Plant and machinery $ 15,206 $ 13,762 Instruments 15,089 13,347 Office equipment 2,114 1,948 Leasehold improvements 10,648 10,480 Total property and equipment–at cost 43,057 39,537 Accumulated depreciation and amortization (21,987 ) (16,956 ) Total property and equipment, net $ 21,070 $ 22,581 Depreciation expense was $5,919,000 , $4,771,000 and $3,510,000 for the years ended December 31, 2018 , 2017 and 2016 , respectively. During the years ended December 31, 2018 , 2017 and 2016 , the Company disposed of certain assets no longer in use with a net book value of $501,000 , $207,000 , and $76,000 , respectively, recorded to cost of revenue, sales and marketing, research and development, or general and administrative expenses based on the asset's respective use.

Loan payable

Loan payable	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Loan payable	Loan Payable As of December 31, 2018 and 2017 , long-term debt consisted of the following (in thousands): December 31, 2018 2017 Term Loans Term Loan A - 6.9% principal $ 7,619 $ 10,000 Term Loan B - 6.9% principal 7,619 10,000 Term Loan C - 7.4% principal 12,000 15,000 Term Loan D - 8.8% principal 663 — Term Loan E - 8.8% principal 7,098 — Final fee obligation 3,288 2,429 Repayment of principal — (7,762 ) Unamortized issuance costs (2,245 ) (1,641 ) Total debt, net 36,042 28,026 Current portion of long-term debt — (7,927 ) Long-term debt $ 36,042 $ 20,099 Term Loans In January 2015, the Company entered into a Loan and Security Agreement, or the LSA, with Solar Capital Partners (as successor-in-interest to General Electric Capital Corporation), and certain other financial institutions party thereto, as lenders, pursuant to which the Company obtained (a) up to $35,000,000 in a series of term loans and (b) a revolving loan in the maximum amount of $5,000,000 . The term loans will accrue interest at a rate equal to ( a) the greater of 1.00% or the 3-year treasury rate in effect at the time of funding, plus (b) an applicable margin between 4.95% and 5.90% per annum. In September 2018, the Company amended its LSA to extend the interest-only period for amounts borrowed by the Company under the Agreement until January 1, 2020 . The Company’s payments are due based upon a 24-month amortization schedule with the remaining outstanding principal and accrued interest amounts due on January 1, 2021 , or the Final Maturity Date. The Company obtained additional term loans of $663,000 and $7,098,000 , respectively, during the year ended December 31, 2018. As of December 31, 2018 , the Company had borrowed all $42,762,000 under the term loans as provided in the LSA, and the Company had not borrowed any of the $5,000,000 available under the revolving loan. The Company will be required to pay a $20,000 annual management fee due on each anniversary of the closing date of the Amendment and a $3,288,000 final payment fee due on the Final Maturity Date. Interest expense recognized on the term loans for the years ended December 31, 2018 , 2017 , and 2016 totaled $2,018,000 , $1,820,000 , and $1,184,000 , respectively. Under the LSA, the Company is required to comply with certain affirmative and negative covenants, including, without limitation, delivering reports and notices relating to the Company’s financial condition and certain regulatory events and intellectual property matters, as well as limiting the creation of liens, the incurrence of indebtedness, and the making of certain investments, dividends, payments and acquisitions, other than as specifically permitted by the LSA. The LSA includes customary events of default, including instances of a material adverse change in our operations, that could require immediate payment of the Company's obligations. As of December 31, 2018 , the Company was in compliance with all covenants under the LSA. Revolving Loan Pursuant to the LSA, the Company may borrow up to $5,000,000 under the revolving loan facility. Borrowings under the revolving loan will accrue interest at a rate equal to (a) the greater of 1.25% per annum or a base rate as determined by a three-month LIBOR-based formula, plus (b) an applicable margin between 2.95% and 3.95% based on certain criteria as set forth in the LSA. All principal and interest outstanding under the revolving loan is due and payable on the Maturity Date. Following the funding of Term Loan A, the Company is required to pay a commitment fee equal to 0.75% per annum of the amounts made available but unborrowed under the revolving loan. As of December 31, 2018 , the Company had not borrowed any amounts pursuant the revolving loan facility. Interest expense recognized for the unused revolving loan facility fee for the years ended December 31, 2018 , 2017 , and 2016 was $35,000 , $35,000 , and $42,000 , respectively. Debt Issuance Costs As of December 31, 2018 and 2017 , the Company had $2,245,000 and $1,641,000 , respectively, of unamortized debt issuance discount, which is offset against borrowings in long-term and short-term debt. For the twelve months ended December 31, 2018 , 2017 , and 2016 , amortization of debt issuance costs were $938,000 , $1,132,000 , and $298,000 , respectively, which was included in interest expense in the Company's consolidated statements of comprehensive loss for the periods presented. Letter of Credit In September 2012, the Company provided a $758,000 letter of credit issued by Banc of California to the landlord of its executive office facility in Carlsbad, California. This letter of credit was secured with $758,000 of restricted cash as of December 31, 2018 .

Employee benefit plan

Employee benefit plan	12 Months Ended
	Dec. 31, 2018
Retirement Benefits [Abstract]
Employee benefit plan	Employee Benefit Plan The Company has a 401(k) tax-deferred savings plan, whereby eligible employees may contribute a percentage of their eligible compensation. The Company makes matching contributions under the 401(k) plan.

Other current liabilities

Other current liabilities	12 Months Ended
	Dec. 31, 2018
Other Current Assets and Liabilities and Other Noncurrent Liabilities [Abstract]
Other current liabilities	Other Current Liabilities Other current liabilities as of December 31, 2018 and 2017 comprised the following (in thousands): December 31, 2018 2017 Accrued royalties $ 534 $ 605 Accrued warranties 330 469 Deferred revenue 245 448 Deferred rent 520 593 Other accrued liabilities 1,414 1,111 Total other current liabilities $ 3,043 $ 3,226

Fair Value of Financial Instrum

Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Fair value of financial instruments	Fair Value of Financial Instruments The following table presents the financial instruments measured at fair value on a recurring basis on the financial statements of the Company and the valuation approach applied to each class of financial instruments at December 31, 2018 and 2017 , respectively, (in thousands): December 31, 2018 Quotes Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Cash equivalents Money market funds $ 8,953 $ — $ — $ 8,953 Marketable securities Corporate notes and bonds — 6,389 — 6,389 Commercial paper — 2,493 — 2,493 Total $ 8,953 $ 8,882 $ — $ 17,835 December 31, 2017 Quotes Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Cash equivalents Money market funds $ 6,362 $ — $ — $ 6,362 Corporate notes and bonds — 1,498 — 1,498 Marketable securities Corporate notes and bonds — 26,278 — 26,278 U.S. government and agency securities — 11,976 — 11,976 Commercial paper — 6,982 — 6,982 Total $ 6,362 $ 46,734 $ — $ 53,096 At December 31, 2018 , the carrying value of the financial instruments measured and classified within Level 1 was based on quoted prices and marked to market. Level 2 inputs for the valuations are limited to quoted prices for similar assets or liabilities in active markets and inputs other than quoted prices that are observable for the asset or liability.

Marketable Securities (Notes)

Marketable Securities (Notes)	12 Months Ended
	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Marketable Securities	Marketable Securities The following table summarizes the Company’s marketable securities at December 31, 2018 and 2017 (in thousands): December 31, 2018 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Corporate notes and bonds $ 6,393 $ — $ (4 ) $ 6,389 U.S. government and agency securities — — — — Commercial paper 2,493 — — 2,493 Total marketable securities $ 8,886 $ — $ (4 ) $ 8,882 December 31, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Corporate notes and bonds $ 26,303 $ — $ (25 ) $ 26,278 U.S. government and agency securities 11,981 — (5 ) 11,976 Commercial paper 6,982 — — 6,982 Total marketable securities $ 45,266 $ — $ (30 ) $ 45,236 The following table summarizes the maturities of the Company’s marketable securities at December 31, 2018 (in thousands): Amortized Cost Estimated Fair Value Due in one year or less $ 8,886 $ 8,882 Total $ 8,886 $ 8,882

Selected Quarterly Financial Da

Selected Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Quarterly financial data (unaudited)	uarterly financial data (unaudited) The following tables show a summary of the Company’s quarterly financial results for each of the four quarters of 2018 and 2017 (in thousands, except for per share amounts): First Quarter Second Quarter Third Quarter Fourth Quarter 2018: Total revenue $ 20,645 $ 14,941 $ 15,795 $ 19,378 Gross profit $ 4,165 $ 4,414 $ 5,630 $ 5,272 Loss from operations $ (10,790 ) $ (15,802 ) $ (10,568 ) $ (10,612 ) Net loss $ (11,423 ) $ (16,521 ) $ (10,993 ) $ (11,563 ) Earnings per share data (1) : Net loss per common share—basic and diluted $ (0.21 ) $ (0.30 ) $ (0.20 ) $ (0.21 ) First Quarter Second Quarter Third Quarter Fourth Quarter 2017: Total revenue $ 12,535 $ 12,359 $ 11,603 $ 16,022 Gross profit $ 6,183 $ 4,884 $ 4,203 $ 4,735 Loss from operations $ (13,556 ) $ (17,267 ) $ (14,731 ) $ (13,963 ) Net loss $ (13,917 ) $ (17,989 ) $ (15,408 ) $ (14,536 ) Earnings per share data (1) : Net loss per common share—basic and diluted $ (0.30 ) $ (0.37 ) $ (0.28 ) $ (0.26 ) (1) Basic and diluted earnings per share are computed independently for each of the quarters presented. As such, the sum of the quarterly basic and diluted earnings per share information may not equal annual basic and diluted earnings per share.

Organization and Basis of Pre_2

Organization and Basis of Presentation Organization and Basis of Presentation (Policies)	12 Months Ended
	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Basis of Presentation	Organization GenMark Diagnostics, Inc., the Company or GenMark, was formed by Osmetech plc, or Osmetech, as a Delaware corporation in February 2010, and had no operations prior to its initial public offering, or the IPO, which was completed in June 2010. Immediately prior to the closing of the IPO, GenMark acquired all of the outstanding ordinary shares of Osmetech in a reorganization, accounted for in a manner similar to a pooling-of-interests, under the applicable laws of the United Kingdom. As a result of the reorganization, all of the issued ordinary shares in Osmetech were cancelled in consideration of (i) the issuance of common stock of GenMark to the former shareholders of Osmetech and (ii) the issuance of new shares in Osmetech to GenMark. Following the reorganization, Osmetech became a subsidiary controlled by GenMark, and the former shareholders of Osmetech received shares of GenMark. Any historical discussion of GenMark relates to Osmetech and its consolidated subsidiaries prior to the reorganization. In September 2012, GenMark placed Osmetech into liquidation to simplify its corporate structure. The liquidation of Osmetech was completed in the fourth quarter of 2013. The Company is a leading provider of multiplex molecular diagnostic solutions designed to enhance patient care, improve key quality metrics, and reduce the total cost-of-care. The Company offers a sample-to-answer ePlex instrument and associated molecular diagnostic panels. The Company's products also include the XT-8 instrument and related diagnostic and research tests, as well as certain custom manufactured reagents, collectively referred to as the XT-8 system. The Company sells its products in the U.S. and Europe directly and through distributors. Basis of Presentation and Principles of Consolidation The accompanying consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles, or U.S. GAAP, and applicable regulations of the U.S. Securities and Exchange Commission, or the SEC. The consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. The accompanying consolidated financial statements have been prepared on a going-concern basis, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business. The Company has incurred net losses from operations since its inception and has an accumulated deficit of $466,883,000 at December 31, 2018 . Management expects operating losses to continue through the foreseeable future. The Company's ability to transition to attaining profitable operations is dependent upon achieving a level of revenues adequate to support its cost structure through expanding its product offerings and consequently increasing its product revenues. Cash, cash equivalents, and marketable securities at December 31, 2018 totaled $45,168,000 . The Company has prepared cash flow forecasts which indicate, based on the Company’s current cash resources available, that the Company will have sufficient resources to fund its business for at least the next 12 months from the date of this filing.
Segment Reporting, Policy	Segment Reporting The Company currently operates as one operating segment. Operating segments are defined as components of an enterprise for which separate financial information is evaluated regularly by the chief operating decision maker, who is the chief executive officer, in deciding how to allocate resources and assessing performance. The Company’s business operates in one operating segment because the Company’s chief operating decision maker evaluates the Company’s financial information and resources and assesses the performance of these resources on a consolidated basis. Since the Company operates in one operating segment, all required financial segment information can be found in the consolidated financial statements.
Use of Estimates, Policy	Use of Estimates The preparation of these consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and the notes thereto. The Company’s significant estimates included in the preparation of the financial statements are related to accounts receivable, inventories, property and equipment, intangible assets, employee-related compensation accruals, warranty liabilities, tax valuation accounts and stock-based compensation. Actual results could differ from those estimates.

Summary of significant accoun_2

Summary of significant accounting policies (Policies)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Cash, Cash Equivalents, and Marketable Securities	Cash and Cash Equivalents and Marketable Securities Cash and cash equivalents consist of cash on deposit with banks, money market instruments, and certificates of deposit with original maturities of three months or less at the date of purchase. Marketable securities consist of certificates of deposits that mature in greater than three months . Marketable securities are accounted for as "available-for-sale" with the carrying amounts reported in the balance sheets stated at cost, which approximates their fair market value, with unrealized gains and losses, if any, reported as a separate component of stockholders' equity and included in comprehensive loss.
Restricted cash policy	Restricted Cash Restricted cash represents amounts designated for uses other than current operations and includes $758,000 as of December 31, 2018 held as security for the Company’s letter of credit with Banc of California.
Fair Value of Financial Instruments, Policy	Fair Value of Financial Instruments The Company uses a fair value hierarchy with three levels of inputs, of which the first two are considered observable and the last unobservable, to measure fair value: • 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 for similar assets or liabilities; quoted prices 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. • 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. The carrying amounts of financial instruments such as accounts receivable, prepaid expenses and other current assets, accounts payable, and accrued liabilities approximate the related fair values due to the short-term maturities of these instruments.
Receivables, Policy	Receivables Accounts receivable consist of amounts due to the Company for sales to customers and are recorded net of an allowance for doubtful accounts. The allowance for doubtful accounts is determined based on an assessment of the collectability of specific customer accounts, the aging of accounts receivable, and a reserve for unknown items based upon the Company’s historical experience. Receivables Accounts receivable consist of amounts due to the Company for sales to customers and are recorded net of an allowance for doubtful accounts. The allowance for doubtful accounts is determined based on an assessment of the collectability of specific customer accounts, the aging of accounts receivable, and a reserve for unknown items based upon the Company’s historical experience. The allowance for doubtful accounts as of December 31, 2018 and 2017 , comprised the following (in thousands): Allowance for doubtful accounts Balance at December 31, 2016 $ 2,740 Provision for doubtful accounts 14 Balance at December 31, 2017 $ 2,754 Provision for doubtful accounts 23 Write off of uncollectible accounts (2,702 ) Balance at December 31, 2018 $ 75 The Company included $2,702,000 in the allowance for doubtful accounts as of December 31, 2017 and 2016 for past due amounts from its former customer, Natural Molecular Testing Corporation (NMTC).
Inventory, Policy	Inventories Inventories are stated at the lower of cost (first-in, first-out) or net realizable value and include direct labor, materials, and manufacturing overhead. The Company periodically reviews inventory for evidence of slow-moving or obsolete parts, and writes inventory down to net realizable value, as needed. This write-down is based on management’s review of inventories on hand, compared to estimated future usage and sales, shelf-life assumptions, and assumptions about the likelihood of obsolescence. If actual market conditions are less favorable than those projected by the Company, additional inventory write-downs may be required. Inventory impairment charges establish a new cost basis for inventory and charges are not reversed subsequently to income, even if circumstances later suggest that increased carrying amounts are recoverable.
Property, Plant and Equipment, Policy	Property and Equipment, net Property, equipment and leasehold improvements are recorded at cost and depreciated using the straight-line method over the estimated useful lives of the assets, which are: Plant and Machinery 3 – 5 years Instruments 4 – 5 years Office equipment 3 – 7 years Leasehold improvements over the shorter of the remaining life of the lease or the useful economic life of the asset Property and equipment includes diagnostic instruments used for sales demonstrations or placed with customers under several types of arrangements, including performance evaluation programs, or PEPs, and reagent rental agreements. Instruments are placed with customers under PEPs for limited evaluation periods. Instruments are also placed with customers under reagent rental agreements, which generally require customers to purchase a minimum number of test cartridges over the term of the agreement. The Company retains title to the instrument under these arrangements. Maintenance and repair costs are expensed as incurred. Leased property meeting certain capital lease criteria is capitalized, and the net present value of the related lease payments is recorded as a liability. Amortization for assets noted as capital leases is recorded using the straight-line method over the shorter of the estimated useful lives or the lease terms.
Intangible Assets, Finite-Lived, Policy	Intangible Assets Intangible assets are comprised of licenses or sublicenses to technology covered by patents owned by third parties, and are amortized on a straight-line basis over the expected useful lives of these assets, which is generally 10 years. Amortization of licenses typically begins upon the Company obtaining access to the licensed technology and is recorded in cost of revenues for licenses supporting commercialized products. The amortization of licenses to technology supporting products in development is recorded in research and development expenses.
Impairment or Disposal of Long-Lived Assets, Policy	Impairment of Long-Lived Assets The Company assesses the recoverability of long-lived assets, including intangible assets, by periodically evaluating the carrying value whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. If impairment is indicated, the Company writes down the carrying value of the asset to its estimated fair value. This fair value is primarily determined based on estimated discounted cash flows. The Company did not recognize any impairment charges during the years ended December 31, 2018 , 2017 , and 2016 .
Revenue Recognition, Policy	Revenue Recognition The Company recognizes revenue from operations through the sale of products and other services. Product revenue is comprised of the sale of consumables and instruments. Revenue is recognized when control of products and services is transferred to the customer in an amount that reflects the consideration that the Company expects to receive from the customer in exchange for those products and services. This process involves identifying the contract with the customer, determining the performance obligations in the contract, determining the contract price, allocating the contract price to the distinct performance obligations in the contract, and recognizing revenue when the performance obligations have been satisfied. A performance obligation is considered distinct from other obligations in a contract when it provides a benefit to the customer either on its own or together with other resources that are readily available to the customer and is separately identified in the contract. The Company considers a performance obligation satisfied once it has transferred control of a good or service to the customer, meaning the customer has the ability to use and obtain the benefit of the good or service. The Company recognizes revenue for satisfied performance obligations only when it determines there are no uncertainties regarding payment terms or transfer of control. Revenue from product sales is recognized generally upon shipment to the end customer, which is when control of the product is deemed to be transferred. Invoicing typically occurs upon shipment and the term between invoicing and when payment is due is not significant. Revenue from instrument services is recognized as the services are rendered, typically evenly over the contract term. Revenue is recorded net of discounts, and sales taxes collected on behalf of governmental authorities. Employee sales commissions are recorded as selling and marketing expenses when incurred or amortized over the estimated contract term when resulting from new contract acquisition efforts. The Company allocates the contract price to each performance obligation in proportion to its stand-alone selling price. The stand-alone selling price is determined by the Company's best estimate of stand-alone selling price using average selling prices over a rolling 12-month period along with a specific assessment of any unique circumstances of the contract. For those products for which there is limited sales history, the Company makes price determinations based on similar product sales data. The following table presents disaggregated revenue by source (in thousands): Year ended December 31, 2018 2017 2016 Revenue Source: ePlex product revenue $ 37,901 $ 10,172 $ 1,478 XT-8 product revenue 32,580 42,088 47,436 Total product revenue 70,481 52,260 48,914 License and other revenue 278 259 360 Total revenue $ 70,759 $ 52,519 $ 49,274 In the years ended December 31, 2018 , 2017 and 2016 , Laboratory Corporation of America, Inc. represented 16% , 20% , and 27% , respectively, of the Company's total revenue. The Company incurs incremental costs to obtain customer contracts including commissions and bonuses
Product Warranties, Policy	Product Warranties The Company generally offers a one -year warranty for its instruments sold to customers and up to a sixty -day warranty for reagents and provides for the estimated cost of the product warranty at the time the system sale is recognized. Factors that affect the Company’s warranty reserves include the number of units sold, historical and anticipated rates of warranty repairs and the cost per warranty repair. The Company periodically assesses and if necessary adjusts the adequacy of the warranty reserve.
Research and Development Expense, Policy	Research and Development Costs The Company expenses all research and development costs in the periods in which they are incurred unless there is alternative future use that supports the capitalization of an asset.
Income Tax, Policy	Income Taxes Current income tax expense is the amount of income taxes expected to be payable for the current year. A deferred income tax liability or asset is established for the expected future tax consequences resulting from the differences in financial reporting and tax bases of assets and liabilities. A valuation allowance is provided if it is more likely than not that some or all of the deferred tax assets will not be realized. A full valuation allowance has been recorded against the Company’s net deferred tax assets due to the uncertainty surrounding the Company’s ability to utilize these assets in the future. The Company provides for uncertain tax positions when such tax positions do not meet the recognition thresholds or measurement standards prescribed by the authoritative guidance on income taxes. Amounts for uncertain tax positions are adjusted in periods when new information becomes available or when positions are effectively settled. The Company recognizes accrued interest related to uncertain tax positions as a component of income tax expense. A tax position that is more likely than not to be realized is measured at the largest amount of tax benefit that is greater than 50% likely of being realized upon settlement with the taxing authority that has full knowledge of all relevant information. Measurement of a tax position that meets the more likely than not threshold considers the amounts and probabilities of the outcomes that could be realized upon settlement using the facts, circumstances and information available at the reporting date.
Share Based Compensation, Policy	Stock-Based Compensation The Company recognizes stock-based compensation expense related to stock options, shares purchased under the Company's 2013 Employee Stock Purchase Plan, or ESPP, restricted stock awards, restricted stock units, and market-based stock units granted to employees and directors in exchange for services. The compensation expense is based on the fair value of the applicable award utilizing various assumptions regarding the underlying attributes of the award. The stock-based compensation expense is recorded in cost of revenues, sales and marketing, research and development, and/or general and administrative expenses based on the employee's respective function. The estimated fair value of stock granted, net of forfeitures expected to occur during the vesting period, is amortized as compensation expense that approximates straight-line expense to reflect vesting as it occurs. The stock option expense is derived from the Black-Scholes option pricing model that uses several judgment-based variables to calculate the expense. The market-based stock expense is derived from the Monte Carlo Simulation Valuation. The inputs utilized in the valuation of the stock-based awards include the following factors: • Expected Term. Expected term represents the period that the stock-based awards are expected to be outstanding and is determined by using the simplified method. • Expected Volatility . Expected volatility represents the expected volatility in the Company’s stock price over the expected term of the option or market-based award and is determined by review of the Company’s and similar companies’ historical experience. • Expected Dividend . The valuation methods requires a single expected dividend yield as an input. The Company assumed no dividends as it has never paid dividends and has no current plans to do so. • Risk-Free Interest Rate. The risk-free interest rate is based on published U.S. Treasury rates in effect at the time of grant for periods corresponding with the expected term of the option or market-based award. The compensation expense related to the grant of restricted stock awards or units is calculated as the fair market value of the stock on the grant date as further adjusted to reflect expected forfeitures.
Foreign Currency Transactions and Translations Policy	Foreign Currency Translation The Company translates the assets and liabilities of the Company's entities outside the U.S. into U.S. Dollars based on the foreign currency exchange rates at the end of each period. Gains or losses resulting from these foreign currency translations are recorded in accumulated comprehensive loss in the consolidated statement of stockholders' equity. Foreign currency translation impacts recorded in accumulated other comprehensive loss (gain) for the years ended December 31, 2018 , 2017 , and 2016 were $44,000 , $(84,000) , and $77,000 , respectively. Revenue and expenses are translated at weighted average exchange rates during the applicable period. Transactions in foreign currencies were recognized using the rate of exchange prevailing at the date of the transaction. Foreign exchange gains (losses), which are included in the accompanying consolidated statements of operations, totaled $(196,000) , $225,000 , and $169,000 for the years ended December 31, 2018 , 2017 and 2016 , respectively, and relate primarily to transactions denominated in Euros.
Earnings Per Share, Policy	Net Loss per Common Share Basic net loss per share is calculated by dividing loss available to stockholders of our common stock (the numerator) by the weighted average number of shares of the Company's common stock outstanding during the period (the denominator). Shares issued during the period and shares reacquired during the period are weighted for the portion of the period that they were outstanding. Diluted loss per share is calculated in a similar way to basic loss per share except that the denominator is increased to include the number of additional shares that would have been outstanding if the dilutive potential shares had been issued unless the effect would be anti-dilutive. The calculations of diluted net loss per share for the years ended December 31, 2018 , 2017 and 2016 did not include the effects of the following stock options or other unvested equity awards which were outstanding as of the end of each year because the inclusion of these securities would have been anti-dilutive (in thousands).
Concentration Risk, Credit Risk, Policy	Concentration of Risk Financial instruments which potentially subject us to concentrations of credit risk consist primarily of cash, cash equivalents, short-term investment securities, and accounts receivable. We limit our exposure to credit loss by placing our cash with high credit quality financial institutions. We have established guidelines relative to diversification of our cash and investment securities and their maturities that are intended to secure safety and liquidity.
Comprehensive Income, Policy	Comprehensive Loss The Company has the option to present the total of comprehensive income, the components of net income, and the components of other comprehensive income either in a single continuous statement of comprehensive income or in two separate but consecutive statements. The Company’s comprehensive loss comprises net losses, unrealized gains and losses on available for sale securities, and foreign currency translation.
New Accounting Pronouncements, Policy	Recent Accounting Pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board, or FASB, or other standard setting bodies that the Company adopts as of the specified effective date. In June 2018, the FASB issued Accounting Standards Update, or ASU 2018-07, Compensation - Stock Compensation (Topic 718), which simplifies the accounting for non-employee share-based payment transactions. The new standard expands the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from non-employees. ASU 2018-07 is effective for fiscal years beginning after December 15, 2018 (including interim periods within that fiscal year), with early adoption permitted. The Company adopted the new standard in the second quarter of 2018 and determined that the application of the new standard did not have a material impact on the Company's consolidated financial statements. In November 2016, the FASB issued ASU, 2016-18, Statement of Cash Flows (Topic 230) Restricted Cash, which requires amounts generally described as restricted cash and restricted cash equivalents to be included in the cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. ASU 2016-18 is effective for fiscal years beginning after December 15, 2017 (including interim periods within those periods) using a retrospective transition method for each period presented, with early adoption permitted. The Company adopted the new standard in the first quarter of 2018 using the retrospective transition method resulting in an increase in the beginning and ending cash balance of $758,000 . In February 2016, the FASB issued ASU 2016-02, Leases, which outlines a comprehensive lease accounting model and supersedes the current lease guidance. The new guidance requires lessees to recognize lease liabilities and corresponding right‑of‑use assets for all leases with lease terms of greater than 12 months. It also changes the definition of a lease and expands the disclosure requirements of lease arrangements. The new guidance must be adopted using the modified retrospective approach and will be effective for the Company starting in the first quarter of 2019, with early adoption permitted. The Company will adopt ASU 2016-02 beginning on January 1, 2019 and will recognize an operating lease liability and operating right-of-use asset in its consolidated balance sheet. The standard will not have a material impact on the Company's finance leases. The Company will no longer present deferred rent in its consolidated balance sheet as it is considered a component of the operating right-of-use asset. The Company will add additional disclosures to its consolidated financial statements surrounding the remaining term and discount rate of its operating leases. In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606), an updated standard on revenue recognition. The new standard provides enhancements to the quality and consistency of how revenue is reported under the principle that revenue should be recognized in an amount that reflects the consideration to which the Company expects to be entitled in exchange for the transfer of promised goods or services. The Company adopted the new standard using the modified retrospective transition method. The cumulative effect of applying the new standard as of January 1, 2018 resulted in a net increase in opening retained earnings of $737,000 to capitalize certain costs to obtain sales contracts. The Company recognized $567,000 in expense related to the amortization of capitalized contract costs during the year ended December 31, 2018 . Aside from this adjustment to beginning retained earnings and the related amortization of expense during the year ended December 31, 2018 , the application of this standard did not have a material impact on the Company's consolidated financial statements as of and for the year ended December 31, 2018 .

Summary of significant accoun_3

Summary of significant accounting policies (Tables)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Schedule of Accounts, Notes, Loans and Financing Receivable	The allowance for doubtful accounts as of December 31, 2018 and 2017 , comprised the following (in thousands): Allowance for doubtful accounts Balance at December 31, 2016 $ 2,740 Provision for doubtful accounts 14 Balance at December 31, 2017 $ 2,754 Provision for doubtful accounts 23 Write off of uncollectible accounts (2,702 ) Balance at December 31, 2018 $ 75
Estimated Useful Lives of Property and Equipment	Property, equipment and leasehold improvements are recorded at cost and depreciated using the straight-line method over the estimated useful lives of the assets, which are: Plant and Machinery 3 – 5 years Instruments 4 – 5 years Office equipment 3 – 7 years Leasehold improvements over the shorter of the remaining life of the lease or the useful economic life of the asset
Schedule of Product Warranty Liability	Product warranty reserve activity for the years ended December 31, 2018 , 2017 and 2016 is as follows (in thousands): 2018 2017 2016 Beginning balance $ 470 $ 219 $ 118 Warranty expenses incurred (1,495 ) (1,160 ) (421 ) Provisions 1,355 1,411 522 Ending balance $ 330 $ 470 $ 219
Schedule of Weighted Average Number of Shares	The calculations of diluted net loss per share for the years ended December 31, 2018 , 2017 and 2016 did not include the effects of the following stock options or other unvested equity awards which were outstanding as of the end of each year because the inclusion of these securities would have been anti-dilutive (in thousands). Year Ended December 31, 2018 2017 2016 Options outstanding to purchase common stock 2,440 2,490 2,570 Other unvested equity awards 2,994 2,307 2,000 Total 5,434 4,797 4,570
Schedules of Concentration of Risk, by Risk Factor	The following table summarizes customers who accounted for 10% or more of net accounts receivable: December 31, 2018 2017 Laboratory Corporation of America, Inc. 24 % 23 %

Intangible Assets, net (Tables)

Intangible Assets, net (Tables)	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of intangible assets	Intangible assets as of December 31, 2018 and 2017 comprised the following (in thousands): December 31, 2018 December 31, 2017 Gross carrying amount Accumulated amortization Net carrying amount Gross carrying amount Accumulated amortization Net carrying amount Licensed intellectual property $ 4,750 $ (2,727 ) $ 2,023 $ 4,750 $ (2,126 ) $ 2,624
Summary of estimated future amortization expense	Estimated future amortization expense for these licenses is as follows (in thousands): Years Ending December 31, Future Amortization Expense 2019 $ 591 2020 591 2021 591 2022 250 Total $ 2,023

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Share-based Compensation, Stock Options, Activity	The following table summarizes stock option activity during the year ended December 31, 2018 : Number of shares Weighted average exercise price Outstanding at December 31, 2017 2,490,465 $ 9.59 Granted — $ — Exercised (5,042 ) $ 4.33 Canceled (45,509 ) $ 11.35 Outstanding at December 31, 2018 2,439,914 $ 9.57 Vested and expected to vest at December 31, 2018 2,439,607 $ 9.57 Exercisable at December 31, 2018 2,416,389 $ 9.54
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions	The assumptions used in the valuation of stock options granted in the years ended December 31, 2018 , 2017 and 2016 , are summarized in the following table: Years Ended December 31, 2018 2017 2016 Expected volatility — % — % 51 % Expected life (years) — — 5.90 Risk free rate — % — % 1.35 % Expected dividend yield — % — % — %
Schedule of Share-based Compensation, Restricted Stock, Award Activity	The Company’s restricted stock unit activity for the year ended December 31, 2018 was as follows: Restricted Stock Units Number of shares Weighted Average Grant Date Fair Value Unvested at December 31, 2017 2,073,440 $ 9.14 Granted 1,827,626 $ 4.55 Vested (953,156 ) $ 9.30 Canceled (282,202 ) $ 7.33 Unvested at December 31, 2018 2,665,708 $ 6.12
Schedule of Share Based Compensation, Market Based Stock Units, Award Activity	The Company’s market-based stock unit activity for the year ended December 31, 2018 was as follows: Market-Based Stock Units Number of Shares Weighted Average Grant Date Fair Value Unvested at December 31, 2017 233,743 $ 10.88 Units granted 320,000 $ 7.19 Vested (108,320 ) $ 7.19 Canceled (116,684 ) $ 6.58 Unvested at December 31, 2018 328,739 $ 10.03
Schedule of Share-based Compensation, Market Based Stock Units, Valuation Assumptions	The fair value of these market-based stock units was estimated on the date of grant using the Monte Carlo Simulation Valuation Model, which estimates the potential outcome of achieving the market condition based on simulated future stock prices, with the following assumptions: Years Ended December 31, 2018 2017 2016 Expected volatility 65 % 54 % 49 % Risk-free interest rate 2.40 % 1.50 % 0.90 % Expected dividend — % — % — % Weighted average fair value $ 7.19 $ 13.82 $ 4.94
Schedule of Share-based Compensation, Employee Stock Purchase Plan, Activity	A summary of ESPP activity for the years ended December 31, 2018 , 2017 , and 2016 is as follows (in thousands, except share and per share data): Years Ended December 31, 2018 2017 2016 Shares issued 252,623 174,723 138,058 Weighted average fair value of shares issued $ 4.20 $ 5.82 $ 6.67 Employee purchases $ 1,061 $ 1,016 $ 921
Schedule of Share-based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions	The assumptions used in the valuation for the years ended December 31, 2018 , 2017 and 2016 , are summarized in the following table: Years Ended December 31, 2018 2017 2016 Expected volatility 73% - 54% 90% - 36% 69% - 52% Expected life (years) 0.50 0.50 0.50 Risk free rate 2.6% - 2.1% 1.5% - 0.6% 0.6% - 0.4% Expected dividend yield — % — % — %
Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs	Stock-based compensation was recognized in the consolidated statements of comprehensive loss as follows (in thousands): Years Ended December 31, 2018 2017 2016 Cost of revenue $ 871 $ 546 $ 258 Sales and marketing 5,549 2,819 2,329 Research and development 2,470 3,039 2,482 General and administrative 2,807 5,766 4,167 Total stock-based compensation expense $ 11,697 $ 12,170 $ 9,236

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Schedule of Income before Income Tax, Domestic and Foreign	The Company's income (loss) before provision (benefit) for income taxes for the years ended December 31, 2018 , 2017 , and 2016 , respectively, was generated in the following jurisdictions (in thousands): Years Ended December 31, 2018 2017 2016 Domestic $ (50,938 ) $ (62,495 ) $ (50,651 ) Foreign 577 746 150 Total loss before income taxes $ (50,361 ) $ (61,749 ) $ (50,501 )
Components of income tax expense (benefit) for continuing operations	The components of income tax expense (benefit) were as follows for the years ended December 31, 2018 , 2017 , and 2016 , respectively (in thousands): Years Ended December 31, 2018 2017 2016 Current expense (benefit): U.S. Federal $ 4 $ (1 ) $ 11 State 43 22 35 Foreign 99 80 51 Total current expense 146 101 97 Deferred expense (benefit): U.S. Federal (5 ) — 2 State (2 ) — 1 Total deferred expense (7 ) — 3 Provision for income taxes $ 139 $ 101 $ 100
Net deferred income taxes	The components of net deferred income taxes consisted of the following at December 31, 2018 and 2017 , respectively (in thousands): As of December 31, 2018 2017 Deferred income tax assets: NOL and credit carryforwards $ 75,063 $ 64,486 Compensation accruals 4,542 4,143 Accruals and reserves 1,401 2,207 State tax provision 7 5 Inventory adjustments 1,193 1,329 Intangible assets 498 455 Other 620 65 Gross deferred tax assets 83,324 72,690 Less: valuation allowance (81,964 ) (71,464 ) Total deferred tax assets 1,360 1,226 Deferred income tax liabilities: Depreciation 1,102 1,226 Contract acquisition costs 258 — Total deferred tax liabilities 1,360 1,226 Net deferred tax assets (liabilities) $ — $ —
Reconciliation of income tax (expense)	A reconciliation of income tax expense to the amount computed by applying the statutory federal income tax rate to the loss from operations is summarized for the years ended December 31, 2018 , 2017 , and 2016 , respectively, as follows: Years Ended December 31, 2018 2017 2016 U.S. Federal statutory income tax rate 21.0 % 34.0 % 34.0 % Permanent differences (0.2 )% (0.2 )% (0.3 )% State taxes 3.0 % 2.8 % 2.3 % Executive compensation limitation (0.5 )% (0.5 )% (0.1 )% Tax reform 0.1 % (59.0 )% — % Stock-based compensation (2.6 )% 1.4 % (3.5 )% Other 0.1 % 0.2 % (0.4 )% Valuation allowance (21.2 )% 21.1 % (32.2 )% Total tax provision (0.3 )% (0.2 )% (0.2 )%

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Annual future minimum obligations for operating leases	Annual future minimum obligations for leases as of December 31, 2018 are as follows (in thousands): Years Ending December 31, Amount 2019 $ 1,989 2020 1,997 2021 2,015 2022 2,077 2023 1,939 Thereafter 2,084 Total minimum lease payments $ 12,101

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2018
Inventory Disclosure [Abstract]
Summary of inventory on hand	Inventory on hand as of December 31, 2018 and 2017 comprised the following (in thousands): December 31, 2018 2017 Raw materials $ 2,449 $ 4,534 Work-in-process 3,349 3,638 Finished goods 4,446 2,777 Total inventory $ 10,244 $ 10,949

Property and Equipment, net (Ta

Property and Equipment, net (Tables)	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment, Net [Abstract]
Property and equipment, net	Property and equipment comprised the following as of December 31, 2018 and 2017 (in thousands): December 31, 2018 2017 Property and equipment–at cost: Plant and machinery $ 15,206 $ 13,762 Instruments 15,089 13,347 Office equipment 2,114 1,948 Leasehold improvements 10,648 10,480 Total property and equipment–at cost 43,057 39,537 Accumulated depreciation and amortization (21,987 ) (16,956 ) Total property and equipment, net $ 21,070 $ 22,581

Loan payable Outstanding Debt (

Loan payable Outstanding Debt (Tables)	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Schedule of Long-term Debt Instruments [Table Text Block]	December 31, 2018 2017 Term Loans Term Loan A - 6.9% principal $ 7,619 $ 10,000 Term Loan B - 6.9% principal 7,619 10,000 Term Loan C - 7.4% principal 12,000 15,000 Term Loan D - 8.8% principal 663 — Term Loan E - 8.8% principal 7,098 — Final fee obligation 3,288 2,429 Repayment of principal — (7,762 ) Unamortized issuance costs (2,245 ) (1,641 ) Total debt, net 36,042 28,026 Current portion of long-term debt — (7,927 ) Long-term debt $ 36,042 $ 20,099

Other current liabilities (Tabl

Other current liabilities (Tables)	12 Months Ended
	Dec. 31, 2018
Other Current Assets and Liabilities and Other Noncurrent Liabilities [Abstract]
Other current liabilities	Other current liabilities as of December 31, 2018 and 2017 comprised the following (in thousands): December 31, 2018 2017 Accrued royalties $ 534 $ 605 Accrued warranties 330 469 Deferred revenue 245 448 Deferred rent 520 593 Other accrued liabilities 1,414 1,111 Total other current liabilities $ 3,043 $ 3,226

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements, Recurring and Nonrecurring [Table Text Block]	The following table presents the financial instruments measured at fair value on a recurring basis on the financial statements of the Company and the valuation approach applied to each class of financial instruments at December 31, 2018 and 2017 , respectively, (in thousands): December 31, 2018 Quotes Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Cash equivalents Money market funds $ 8,953 $ — $ — $ 8,953 Marketable securities Corporate notes and bonds — 6,389 — 6,389 Commercial paper — 2,493 — 2,493 Total $ 8,953 $ 8,882 $ — $ 17,835 December 31, 2017 Quotes Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Cash equivalents Money market funds $ 6,362 $ — $ — $ 6,362 Corporate notes and bonds — 1,498 — 1,498 Marketable securities Corporate notes and bonds — 26,278 — 26,278 U.S. government and agency securities — 11,976 — 11,976 Commercial paper — 6,982 — 6,982 Total $ 6,362 $ 46,734 $ — $ 53,096

Marketable Securities (Tables)

Marketable Securities (Tables)	12 Months Ended
	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Marketable securities - Gross unrealized gains/losses	The following table summarizes the Company’s marketable securities at December 31, 2018 and 2017 (in thousands): December 31, 2018 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Corporate notes and bonds $ 6,393 $ — $ (4 ) $ 6,389 U.S. government and agency securities — — — — Commercial paper 2,493 — — 2,493 Total marketable securities $ 8,886 $ — $ (4 ) $ 8,882 December 31, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Corporate notes and bonds $ 26,303 $ — $ (25 ) $ 26,278 U.S. government and agency securities 11,981 — (5 ) 11,976 Commercial paper 6,982 — — 6,982 Total marketable securities $ 45,266 $ — $ (30 ) $ 45,236
Marketable Securities - Contractual Maturities	The following table summarizes the maturities of the Company’s marketable securities at December 31, 2018 (in thousands): Amortized Cost Estimated Fair Value Due in one year or less $ 8,886 $ 8,882 Total $ 8,886 $ 8,882

Selected Quarterly Financial _2

Selected Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data	First Quarter Second Quarter Third Quarter Fourth Quarter 2018: Total revenue $ 20,645 $ 14,941 $ 15,795 $ 19,378 Gross profit $ 4,165 $ 4,414 $ 5,630 $ 5,272 Loss from operations $ (10,790 ) $ (15,802 ) $ (10,568 ) $ (10,612 ) Net loss $ (11,423 ) $ (16,521 ) $ (10,993 ) $ (11,563 ) Earnings per share data (1) : Net loss per common share—basic and diluted $ (0.21 ) $ (0.30 ) $ (0.20 ) $ (0.21 ) First Quarter Second Quarter Third Quarter Fourth Quarter 2017: Total revenue $ 12,535 $ 12,359 $ 11,603 $ 16,022 Gross profit $ 6,183 $ 4,884 $ 4,203 $ 4,735 Loss from operations $ (13,556 ) $ (17,267 ) $ (14,731 ) $ (13,963 ) Net loss $ (13,917 ) $ (17,989 ) $ (15,408 ) $ (14,536 ) Earnings per share data (1) : Net loss per common share—basic and diluted $ (0.30 ) $ (0.37 ) $ (0.28 ) $ (0.26 ) (1) Basic and diluted earnings per share are computed independently for each of the quarters presented. As such, the sum of the quarterly basic and diluted earnings per share information may not equal annual basic and diluted earnings per share.

Organization and Basis of Pre_3

Organization and Basis of Presentation (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accumulated deficit	$ (466,883,000)	$ (416,383,000)
Cash, cash equivalents, and marketable securities	$ 45,168,000

Summary of significant accoun_4

Summary of significant accounting policies - Cash, Cash Equivalents, Restricted Cash, and Marketable Securities (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Accounting Policies [Abstract]
Restricted cash	$ 758,000	$ 758,000
Minimum Maturity for Short Term Investments	3 months
Maximum Maturity for Cash and Cash Equivalent at Date of Purchase	3 months

Summary of significant accoun_5

Summary of significant accounting policies - Allowance for Doubtful Accounts Receivable Rollforward (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Doubtful Accounts	$ 2,754,000	$ 2,740,000	$ 2,740,000
Allowance for Doubtful Accounts Receivable, Write-offs	(2,702,000)
Beginning Balance	2,754,000	2,740,000
Provision for Doubtful Accounts	23,000	14,000	13,000
Ending Balance	75,000	$ 2,754,000	$ 2,740,000
Natural Molecular Testing Corporation
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Doubtful Accounts	2,702,000
Ending Balance	$ 2,702,000

Summary of significant accoun_6

Summary of significant accounting policies - Property, Plant, and Equipment (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accounting Policies [Abstract]
Finite-Lived Intangible Asset, Useful Life	10 years
Asset Impairment Charges	$ 0	$ 0	$ 0
Machinery and Equipment | Minimum
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Machinery and Equipment | Maximum
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Instruments | Minimum
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	4 years
Instruments | Maximum
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Office Equipment | Minimum
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Office Equipment | Maximum
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	7 years

Summary of significant accoun_7

Summary of significant accounting policies - Product Warranty (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Movement in Standard and Extended Product Warranty Accrual, Increase (Decrease) [Roll Forward]
Beginning balance	$ 470	$ 219	$ 118
Warranty expenses incurred	1,495	1,160	421
Provisions	1,355	1,411	522
Ending balance	$ 330	$ 470	$ 219
Systems [Member]
Product Warranty Liability [Line Items]
Products Warranty Period	1 year
Reagents [Member]
Product Warranty Liability [Line Items]
Products Warranty Period	60 days

Summary of significant accoun_8

Summary of significant accounting policies - Foreign Currency Translation (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accounting Policies [Abstract]
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	$ 44,000	$ (84,000)	$ 77,000
Foreign Currency Transaction Gain (Loss), before Tax		$ 225,000	$ 169,000

Summary of significant accoun_9

Summary of significant accounting policies - Earnings per share (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	5,434	4,797	4,570
Employee Stock Option
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	2,440	2,490	2,570
Equity award, Non stock option member [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	2,994	2,307	2,000

Summary of significant accou_10

Summary of significant accounting policies - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accounting Policies [Abstract]
Percentage of Tax Benefit Likely of Being Realized upon Settlement	50.00%
Operating Loss Carryforwards, Excess Tax Benefits Related To Share-Based Compensation	$ 1,976,000
Customer Concentration Risk | Laboratory Corporation of America Inc.
Concentration Risk [Line Items]
Concentration Risk, Percentage	16.00%	20.00%	27.00%
Credit Concentration Risk | Laboratory Corporation of America Inc.
Concentration Risk [Line Items]
Concentration Risk, Percentage	24.00%	23.00%

Summary of significant accou_11

Summary of significant accounting policies Contract acquisition (Details)	12 Months Ended
	Dec. 31, 2018USD ($)
Revenue from Contract with Customer [Abstract]
Cumulative Effect on Retained Earnings, Net of Tax	$ 737,000
Capitalized Contract Cost, Net	1,055,000
Capitalized Contract Cost, Amortization	$ 567,000

Intangible Assets - Components

Intangible Assets - Components of Gross and Net Intangible Asset Balances (Details) - USD ($)	1 Months Ended	12 Months Ended
	Jul. 31, 2012	Dec. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Net		$ 2,023,000
Licensed Intellectual Property [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount		4,750,000	$ 4,750,000
Accumulated amortization		2,727,000	2,126,000
Finite-Lived Intangible Assets, Net		2,023,000	$ 2,624,000
Advanced Liquid Logic, Inc. [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired	$ 250,000	$ 500,000
Indefinite-Lived License Agreements, Potential Cash Payment	$ 1,750,000

Intangible Assets, net - Additi

Intangible Assets, net - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense for intangible assets	$ 601,000	$ 546,000	$ 406,000
Finite-Lived Intangible Assets, Remaining Amortization Period	3 years 5 months 5 days

Intangible Assets - Future Amor

Intangible Assets - Future Amortization Expense (Details) $ in Thousands	Dec. 31, 2018USD ($)
Summary of estimated future amortization expense
2,018	$ 591
2,019	591
2,020	591
2,021	250
Net carrying amount	$ 2,023

Stockholders' Equity (Details)

Stockholders' Equity (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Class of Stock [Line Items]
Proceeds from issuance of common stock	$ 1,061,000	$ 87,267,000	$ 30,920,000
Payments of Stock Issuance Costs	$ 0	$ 5,469,000	1,143,000
Equity Offering [Member]
Class of Stock [Line Items]
Shares available for sale	6,382,978
Underwriter Option to Purchase Shares	957,446
Payments of Stock Issuance Costs	$ 5,520,000
Underwriting Fees	5,175,000
Fees and Commissions	$ 345,000
Equity Offering [Member] | Common Stock [Member]
Class of Stock [Line Items]
Shares Issued, Price Per Share	$ 11.75
Stock Issued During Period, Shares, New Issues	7,340,424
Proceeds from issuance of common stock	$ 86,250,000
ATM Offering [Member]
Class of Stock [Line Items]
Commission Percentage		3.00%
Maximum ATM Offering		$ 30,000,000
Payments of Stock Issuance Costs		1,143,000
Underwriting Fees		900,000
Fees and Commissions		$ 243,000
ATM Offering [Member] | Common Stock [Member]
Class of Stock [Line Items]
Shares Issued, Price Per Share		$ 9.04
Stock Issued During Period, Shares, New Issues		3,300,000
Proceeds from issuance of common stock		$ 30,000,000
Restricted Stock Awards | 2010 Equity Incentive Plan
Class of Stock [Line Items]
Equity Instruments Other than Options, Vested in Period, Fair Value	$ 645,000		$ 2,433,000

Stock-Based Compensation Stock

Stock-Based Compensation Stock Awards Activity (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Issued During Period, Value, Employee Stock Purchase Plan	$ 1,061,000	$ 1,016,000	$ 921,000
2010 Equity Incentive Plan | Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options outstanding	2,439,914	2,490,465
Options granted	0
Options exercised	5,042
Options canceled	(45,509)
Options, Vested and Expected to Vest	2,439,607
Options, Exercisable	2,416,389
Options, Outstanding, Weighted Average Exercise Price	$ 9.57	$ 9.59
Options, Grants in Period, Weighted Average Exercise Price	0
Options, Exercises in Period, Weighted Average Exercise Price	4.33
Options, Canceled in Period, Weighted Average Exercise Price	11.35
Options, Vested and Expected to Vest, Weighted Average Exercise Price	9.57
Options, Exercisable, Weighted Average Exercise Price	$ 9.54
Options, Exercisable, Weighted Average Remaining Contractual Term	3 years 9 months 26 days
Options, Exercisable, Intrinsic Value	$ 290,000
Options, Exercises in Period, Intrinsic Value	$ 6,700	$ 173,000	184,000
Options, Outstanding, Weighted Average Remaining Contractual Term	3 years 10 months 2 days
Options, Outstanding, Intrinsic Value	$ 290,300
Nonvested Awards, Compensation Cost Not yet Recognized, Weighted Average Period for Recognition	1 month 28 days
Nonvested Awards, Compensation Cost Not yet Recognized	$ 75,000
2010 Equity Incentive Plan | Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity Instruments Other than Options, Vested in Period, Fair Value	$ 645,000		2,433,000
2010 Equity Incentive Plan | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity Award Other Than Options, Unvested	2,665,708	2,073,440
Equity Award Other Than Options, Grants in Period	1,827,626
Equity Award Other Than Options, Vested in Period	(953,156)
Equity Award Other Than Options, Forfeited in Period	(282,202)
Equity Award Other Than Options, Weighted Average Grant Date Fair Value	$ 6.12	$ 9.14
Equity Award Other Than Options, Grants in Period, Weighted Average Grant Date Fair Value	4.55
Equity Award Other Than Options, Vested in Period, Weighted Average Grant Date Fair Value	9.30
Equity Award Other Than Options, Canceled in Period, Weighted Average Grant Date Fair Value	$ 7.33
Equity Instruments Other than Options, Vested in Period, Fair Value	$ 5,404,000	$ 7,813,000	$ 3,192,000
Nonvested Awards, Compensation Cost Not yet Recognized, Weighted Average Period for Recognition	2 years 5 months 16 days
Nonvested Awards, Compensation Cost Not yet Recognized	$ 11,098,000
2010 Equity Incentive Plan | Market Share Unit
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity Award Other Than Options, Unvested	328,739	233,743
Equity Award Other Than Options, Grants in Period	320,000
Equity Award Other Than Options, Vested in Period	(108,320)
Equity Award Other Than Options, Canceled in Period	(116,684)
Equity Award Other Than Options, Weighted Average Grant Date Fair Value	$ 10.03	$ 10.88
Equity Award Other Than Options, Grants in Period, Weighted Average Grant Date Fair Value	7.19	$ 13.82	$ 4.94
Equity Award Other Than Options, Vested in Period, Weighted Average Grant Date Fair Value	7
Equity Award Other Than Options, Canceled in Period, Weighted Average Grant Date Fair Value	$ 6.58
Equity Instruments Other than Options, Vested in Period, Fair Value		$ 0
Nonvested Awards, Compensation Cost Not yet Recognized, Weighted Average Period for Recognition	1 year 6 months 29 days
Nonvested Awards, Compensation Cost Not yet Recognized	$ 1,283,000
2010 Equity Incentive Plan | Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity Award Other Than Options, Grants in Period				43,200
Equity Award Other Than Options, Vested in Period				(10,800)
Equity Award Other Than Options, Forfeited in Period	(10,800)	(10,800)	(10,800)
Equity Award Other Than Options, Vested in Period, Weighted Average Grant Date Fair Value				$ 12.30
Equity Instruments Other than Options, Vested in Period, Fair Value			$ 147,000
2013 Employee Stock Purchase Plan | Employee Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity Award Other Than Options, Vested in Period, Weighted Average Grant Date Fair Value	$ 4.20	$ 5.82	$ 6.67
Stock Issued During Period, Value, Employee Stock Purchase Plan	$ 1,061,000	$ 1,016,000	$ 921,000
Stock Issued During Period, Shares, Employee Stock Purchase Plans	252,623	174,723	138,058

Stock-Based Compensation Valuat

Stock-Based Compensation Valuation Assumptions (Details) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
2010 Equity Incentive Plan | Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair Value Assumptions, Expected Volatility Rate	0.00%	0.00%	51.00%
Fair Value Assumptions, Expected Term	0 years		5 years 10 months 24 days
Fair Value Assumptions, Risk Free Interest Rate	0.00%	0.00%	1.35%
Fair Value Assumptions, Expected Dividend Rate	0.00%	0.00%	0.00%
2010 Equity Incentive Plan | Market Share Unit
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair Value Assumptions, Expected Volatility Rate	65.00%	54.00%	49.00%
Fair Value Assumptions, Risk Free Interest Rate	2.40%	1.50%	0.90%
Fair Value Assumptions, Expected Dividend Rate	0.00%	0.00%	0.00%
Equity Award Other Than Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 7.19	$ 13.82	$ 4.94
2013 Employee Stock Purchase Plan | Employee Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair Value Assumptions, Expected Term	6 months	6 months	6 months
Fair Value Assumptions, Expected Dividend Rate	0.00%	0.00%	0.00%
2013 Employee Stock Purchase Plan | Employee Stock | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair Value Assumptions, Expected Volatility Rate	90.00%	69.00%	63.00%
Fair Value Assumptions, Risk Free Interest Rate	1.50%	0.60%	0.40%
2013 Employee Stock Purchase Plan | Employee Stock | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair Value Assumptions, Expected Volatility Rate	36.00%	52.00%	43.00%
Fair Value Assumptions, Risk Free Interest Rate	0.60%	0.40%	0.10%

Stock-Based Compensation Expens

Stock-Based Compensation Expense Recognition (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated Share-based Compensation Expense	$ 11,697,000	$ 12,170,000	$ 9,236,000
Allocation of Recognized Period Costs, Capitalized Amount	0	0	0
Unrecognized Deferred Tax Assets Related to Excess Tax Benefits from Share Based Compensation	0	0	0
Cost of revenue
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated Share-based Compensation Expense	871,000	546,000	258,000
Sales and marketing
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated Share-based Compensation Expense	5,549,000	2,819,000	2,329,000
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated Share-based Compensation Expense	2,470,000	3,039,000	2,482,000
General and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated Share-based Compensation Expense	$ 2,807,000	$ 5,766,000	$ 4,167,000

Stock-Based Compensation Additi

Stock-Based Compensation Additional Information (Details)	12 Months Ended
	Dec. 31, 2018Rateshares
2010 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares Available for Grant	539,902
2010 Equity Incentive Plan | Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award Vesting Period	4 years
Expiration Period	10 years
2010 Equity Incentive Plan | Market Share Unit
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum MSU Payout Percentage | Rate	200.00%
Award Vesting Period	3 years
2013 Employee Stock Purchase Plan | Employee Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares Authorized	1,750,000
Number of Shares Available for Grant	940,493
Purchase Price of Common Stock, Percent	85.00%
Offering Period	6 months
Maximum Employee Subscription Rate	10.00%
Maximum Number of Shares Per Employee	1,500
Maximum | 2013 Employee Stock Purchase Plan | Employee Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Offering Period	27 months

Income Taxes - Schedule Of Inco

Income Taxes - Schedule Of Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Domestic	$ (50,938)	$ (62,495)	$ (50,651)
Foreign	577	746	150
Loss before provision for income taxes	$ (50,361)	$ (61,749)	$ (50,501)

Income Taxes - Components Of In

Income Taxes - Components Of Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current expense (benefit):
U.S. Federal	$ 4	$ (1)	$ 11
State	43	22	35
Foreign (non-U.S. entities)	99	80	51
Total current expense	146	101	97
Deferred expense (benefit):
U.S. Federal	(5)	0	2
State	(2)	0	1
Total deferred expense	(7)	0	3
Income Tax Expense (Benefit)	$ 139	$ 101	$ 100

Income Taxes - Deferred Income

Income Taxes - Deferred Income Tax Assets and Liabilities (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Deferred Tax Assets, Gross [Abstract]
NOL and credit carryforwards	$ 75,063,000	$ 64,486,000
Compensation accruals	4,542,000	4,143,000
Accruals and reserves	1,401,000	2,207,000
State tax provision	7,000	5,000
Inventory adjustments	1,193,000	1,329,000
Intangible assets	498,000	455,000
Other	620,000	65,000
Gross deferred tax assets	83,324,000	72,690,000
Less: valuation allowance	(81,964,000)	(71,464,000)
Total deferred tax assets	1,360,000	1,226,000
Deferred Tax Liabilities, Net [Abstract]
Depreciation	1,102,000	1,226,000
Contract acquisition costs	258,000	0
Total deferred tax liabilities	1,360,000	1,226,000
Net deferred tax assets (liabilities)	$ 0	$ 0

Income Taxes - Effective Income

Income Taxes - Effective Income Tax Rate Reconcilation (Details)	Jan. 01, 2018Rate	Dec. 31, 2018Rate	Dec. 31, 2017	Dec. 31, 2017Rate	Dec. 31, 2016Rate
Effective Income Tax Rate Reconciliation
U.S. Federal statutory income tax rate	21.00%	21.00%	34.00%	34.00%	34.00%
Permanent differences		(0.20%)	(0.20%)		(0.30%)
State taxes		3.00%	2.80%		2.30%
Executive compensation limitation		(0.50%)	(0.50%)		(0.10%)
Tax reform		0.10%		(59.00%)	0.00%
Stock-based compensation		(2.60%)	1.40%		(3.50%)
Other		0.10%	0.20%		(0.40%)
Valuation allowance		(21.20%)	21.10%		(32.20%)
Effective Income Tax Rate Reconciliation, Percent		(0.30%)	(0.20%)		(0.20%)

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details Textual) - USD ($)	Jan. 01, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Valuation Allowance		$ 81,964,000	$ 71,464,000	$ 71,464,000
Operating Loss Carryforwards, Excess Tax Benefits Related To Share-Based Compensation		$ 1,976,000
Percentage of Holding by Stockholders Under Consideration to Offset Future Taxable Income		stockholders that hold 5% or more of the Company’s common stock
Probability of Realization of Income Tax upon Settlement		50.00%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	21.00%	34.00%	34.00%	34.00%
Unrecognized Tax Benefits		$ 0	$ 0	$ 0	$ 0
Domestic Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards		$ 306,800,000
Net operating loss carryforwards, Expiration date		Jan. 1, 2025
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards		$ 215,000,000
Net operating loss carryforwards, Expiration date		Jan. 1, 2019

Commitments and Contingencies_2

Commitments and Contingencies (Details) $ in Thousands	Dec. 31, 2018USD ($)
Annual future minimum obligations for operating leases
2,018	$ 1,989
2,019	1,997
2,020	2,015
2,021	2,077
2,022	1,939
Thereafter	2,084
Total minimum lease payments	$ 12,101

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Loss Contingencies [Line Items]
Operating Leases, Rent Expense	$ 1,808,000	$ 1,654,000	$ 1,871,000
Deferred balance	$ 3,516,000	$ 3,652,000
Lease Expiration Date	Jun. 1, 2025
Minimum
Loss Contingencies [Line Items]
Payments for (Proceeds from) Loans and Leases	$ 107,000
Maximum
Loss Contingencies [Line Items]
Payments for (Proceeds from) Loans and Leases	$ 117,000

Inventories (Details)

Inventories (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Summary of inventory on hand
Raw materials	$ 2,449	$ 4,534
Work-in-process	3,349	3,638
Finished goods	4,446	2,777
Total inventory	$ 10,244	$ 10,949

Property and Equipment, net (De

Property and Equipment, net (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Property and equipment-at cost:
Total property and equipment-at cost	$ 43,057	$ 39,537
Less accumulated depreciation	(21,987)	(16,956)
Net property and equipment	21,070	22,581
Plant and machinery
Property and equipment-at cost:
Total property and equipment-at cost	15,206	13,762
Instruments
Property and equipment-at cost:
Total property and equipment-at cost	15,089	13,347
Office equipment
Property and equipment-at cost:
Total property and equipment-at cost	2,114	1,948
Leasehold improvements
Property and equipment-at cost:
Total property and equipment-at cost	$ 10,648	$ 10,480

Property and Equipment, net - A

Property and Equipment, net - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment, Net [Abstract]
Property, Plant and Equipment, Disposals	$ 501,000	$ 207,000	$ 76,000
Depreciation expense	$ 5,919,000	$ 4,771,000	$ 3,510,000

Loan payable Schedule Term Loan

Loan payable Schedule Term Loans (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Debt Instrument, Fee	20,000
Long-term Debt, Current Maturities	$ 0	$ (7,927,000)
Long-term Debt, Excluding Current Maturities	36,042,000	20,099,000
Restricted cash	758,000	758,000
Revolving Credit Facility
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 5,000,000
Line of Credit Facility, Interest Rate Description	(a) the greater of 1.25% per annum or a base rate as determined by a three-month LIBOR-based formula, plus (b) an applicable margin between 2.95% and 3.95%
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage	0.75%
Debt Instrument, Unused Borrowing Capacity, Fee	$ 35,000	35,000	$ 42,000
Letter of Credit [Member]
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount	758,000
Restricted cash	758,000
Term Loans
Debt Instrument [Line Items]
Term Loans, Debt Facility, Maximum Borrowing Capacity	$ 35,000,000
Debt Instrument, Interest Rate Terms	a) the greater of 1.00% or the 3-year treasury rate in effect at the time of funding, plus (b) an applicable margin between 4.95% and 5.90% per annum.
Long-term Debt, Gross	$ 42,762,000
Loans Payable, Final Fee Obligation	3,288,000	2,429,000
Debt Instrument, Annual Principal Payment	0	(7,762,000)
Debt Instrument, Unamortized Discount (Premium), Net	(2,245,000)
Long-term Debt	36,042,000	28,026,000
Long-term Debt, Current Maturities	0	(7,927,000)
Long-term Debt, Excluding Current Maturities	36,042,000	20,099,000
Interest Expense, Debt	2,018,000	1,820,000	1,184,000
Amortization of Debt Issuance Costs	$ 938,000	1,132,000	$ 298,000
Term Loans | Interest-only period
Debt Instrument [Line Items]
Debt Interest only Period End	Jan. 1, 2020
Term Loans | Final Maturity
Debt Instrument [Line Items]
Debt Instrument, Maturity Date	Jan. 1, 2021
Unamortized issuance cost [Member]
Debt Instrument [Line Items]
Debt Instrument, Unamortized Discount (Premium), Net		(1,641,000)
Term Loan A
Debt Instrument [Line Items]
Long-term Debt	$ 7,619,000	10,000,000
Debt Instrument, Interest Rate, Stated Percentage	6.90%
Term Loan B
Debt Instrument [Line Items]
Long-term Debt	$ 7,619,000	10,000,000
Debt Instrument, Interest Rate, Stated Percentage	6.90%
Term Loan C
Debt Instrument [Line Items]
Long-term Debt	$ 12,000,000	15,000,000
Debt Instrument, Interest Rate, Stated Percentage	7.40%
Term Loan D [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 663,000	0
Term Loan D [Domain]
Debt Instrument [Line Items]
Long-term Debt	663,000
Term Loan E [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 7,098,000	$ 0

Other current liabilities (Deta

Other current liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Other current liabilities
Accrued royalties	$ 534	$ 605
Accrued warranties	330	469
Deferred revenue	245	448
Deferred Rent Credit, Current	520	593
Other Accrued Liabilities, Current	1,414	1,111
Total	$ 3,043	$ 3,226

Fair Value of Financial Instr_3

Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Assets measured at fair value on a recurring basis
Financial instruments, fair value	$ 17,835	$ 53,096
Level 1
Assets measured at fair value on a recurring basis
Financial instruments, fair value	8,953	6,362
Level 2
Assets measured at fair value on a recurring basis
Financial instruments, fair value	8,882	46,734
Level 3
Assets measured at fair value on a recurring basis
Financial instruments, fair value	0	0
Fair Value, Measurements, Recurring | Money Market Funds
Assets measured at fair value on a recurring basis
Cash and Cash Equivalents	8,953	6,362
Fair Value, Measurements, Recurring | Money Market Funds | Level 1
Assets measured at fair value on a recurring basis
Cash and Cash Equivalents	8,953	6,362
Fair Value, Measurements, Recurring | Money Market Funds | Level 2
Assets measured at fair value on a recurring basis
Cash and Cash Equivalents	0	0
Fair Value, Measurements, Recurring | Money Market Funds | Level 3
Assets measured at fair value on a recurring basis
Cash and Cash Equivalents	0	0
Fair Value, Measurements, Recurring | Corporate Notes and Bonds
Assets measured at fair value on a recurring basis
Marketable securities	6,389	26,278
Fair Value, Measurements, Recurring | Corporate Notes and Bonds | Level 1
Assets measured at fair value on a recurring basis
Marketable securities	0	0
Fair Value, Measurements, Recurring | Corporate Notes and Bonds | Level 2
Assets measured at fair value on a recurring basis
Marketable securities	6,389	26,278
Fair Value, Measurements, Recurring | Corporate Notes and Bonds | Level 3
Assets measured at fair value on a recurring basis
Marketable securities	0	0
Fair Value, Measurements, Recurring | U.S. Government and Agency Securities
Assets measured at fair value on a recurring basis
Marketable securities		11,976
Fair Value, Measurements, Recurring | U.S. Government and Agency Securities | Level 1
Assets measured at fair value on a recurring basis
Marketable securities		0
Fair Value, Measurements, Recurring | U.S. Government and Agency Securities | Level 2
Assets measured at fair value on a recurring basis
Marketable securities		11,976
Fair Value, Measurements, Recurring | U.S. Government and Agency Securities | Level 3
Assets measured at fair value on a recurring basis
Marketable securities		0
Fair Value, Measurements, Recurring | Commercial paper
Assets measured at fair value on a recurring basis
Marketable securities	2,493	6,982
Fair Value, Measurements, Recurring | Commercial paper | Level 1
Assets measured at fair value on a recurring basis
Marketable securities	0	0
Fair Value, Measurements, Recurring | Commercial paper | Level 2
Assets measured at fair value on a recurring basis
Marketable securities	2,493	6,982
Fair Value, Measurements, Recurring | Commercial paper | Level 3
Assets measured at fair value on a recurring basis
Marketable securities	$ 0	$ 0

Marketable Securities - Gross

Marketable Securities - Gross unrealized gains/losses on marketable securities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 8,886	$ 45,266
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(4)	(30)
Estimated Fair Value	8,882	45,236
Corporate notes and bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	6,393	26,303
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(4)	(25)
Estimated Fair Value	6,389	26,278
U.S. government and agency securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	0	11,981
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	(5)
Estimated Fair Value	0	11,976
Commercial paper
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	2,493	6,982
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	$ 2,493	$ 6,982

Marketable Securities - Contra

Marketable Securities - Contractual maturities of marketable securities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 8,886	$ 45,266
Estimated Fair Value	8,882	$ 45,236
Due in one year or less
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	8,886
Estimated Fair Value	$ 8,882

Marketable Securities - Additi

Marketable Securities - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Gain (Loss) on Sale of Equity Investments	$ 0	$ 0	$ 9

Selected Quarterly Financial _3

Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Selected Quarterly Financial Data
Total revenue	$ 19,378	$ 15,795	$ 14,941	$ 20,645	$ 16,022	$ 11,603	$ 12,359	$ 12,535	$ 70,759	$ 52,519	$ 49,274
Gross profit	5,272	5,630	4,414	4,165	4,735	4,203	4,884	6,183	19,481	20,005	29,574
Loss from operations	(10,612)	(10,568)	(15,802)	(10,790)	(13,963)	(14,731)	(17,267)	(13,556)	(47,772)	(59,517)	(48,981)
Net loss	$ (11,563)	$ (10,993)	$ (16,521)	$ (11,423)	$ (14,536)	$ (15,408)	$ (17,989)	$ (13,917)	$ (50,500)	$ (61,850)	$ (50,601)
Per share data:
Net loss per common share - basic and diluted	$ (0.21)	$ (0.20)	$ (0.30)	$ (0.21)	$ (0.26)	$ (0.28)	$ (0.37)	$ (0.30)	$ (0.91)	$ (1.21)	$ (1.15)

Subsequent Events (Details)

Subsequent Events (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)
Subsequent Event [Line Items]
Repayments of Debt	$ 38.8
Debt Instrument, Redemption, Period One [Member]
Subsequent Event [Line Items]
Debt Instrument, Maturity Date	Feb. 28, 2021
Debt Instrument, Redemption, Period Two [Member]
Subsequent Event [Line Items]
Debt Instrument, Maturity Date	Feb. 28, 2022
Debt Instrument, Redemption, Period Three [Member]
Subsequent Event [Line Items]
Debt Instrument, Maturity Date	Feb. 1, 2023
Tranche 2 Loan [Member]
Subsequent Event [Line Items]
Long-term Debt, Gross	$ 15
Tranche 1 Loan [Member]
Subsequent Event [Line Items]
Long-term Debt, Gross	$ 50