nLIGHT (LASR) 10-Q 7 Aug 19 2019 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2019	Aug. 02, 2019
Document and Entity Information [Abstract]
Entity Registrant Name	nLIGHT, Inc.
Entity Central Index Key	0001124796
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Document Type	10-Q
Document Period End Date	Jun. 30, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Entity Current Reporting Status	Yes
Amendment Flag	false
Smaller Reporting Company	false
Emerging Growth	true
Entity Shell Company	false
Entity Ex Transition Period	false
Entity Common Stock, Shares Outstanding		37,687,755

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 142,661	$ 149,478
Accounts receivable, net of allowances of $329 and $303	30,752	26,528
Inventory	42,285	35,329
Prepaid expenses and other current assets	4,107	7,286
Total current assets	219,805	218,621
Property and equipment, net of accumulated depreciation of $55,933 and $53,812	24,650	21,462
Intangible assets, net of accumulated amortization of $2,410 and $2,049	2,971	2,686
Goodwill	1,387	1,387
Other assets	6,776	5,974
Total assets	255,589	250,130
Current liabilities:
Accounts payable	13,360	12,068
Accrued liabilities	10,693	10,708
Deferred revenues	582	720
Current portion of long-term debt	78	91
Total current liabilities	24,713	23,587
Non-current income taxes payable	6,854	6,472
Long-term debt	17	18
Other long-term liabilities	2,068	2,270
Total liabilities	33,652	32,347
Stockholders' equity:
Preferred stock - $0.0001 par value; 5,000 shares authorized, zero shares issued and outstanding at June 30, 2019 and December 31, 2018.	0	0
Common stock - $0.0001 par value; 190,000 shares authorized, 37,665 shares issued and outstanding at June 30, 2019 and 190,000 shares authorized, 36,705 shares issued and outstanding at December 31, 2018.	15	15
Additional paid-in capital	329,982	324,656
Accumulated other comprehensive loss	(2,100)	(2,157)
Accumulated deficit	(105,960)	(104,731)
Total stockholders’ equity	221,937	217,783
Total liabilities and stockholders’ equity	$ 255,589	$ 250,130

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Accounts receivable, allowances	$ 329	$ 303
Property and equipment, accumulated depreciation	55,933	53,812
Intangible assets, accumulated amortization	$ 2,410	$ 2,049
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	190,000,000	190,000,000
Common stock, shares issued (in shares)	37,665,000	36,705,000
Common stock, shares outstanding (in shares)	37,665,000	36,705,000

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Statement [Abstract]
Revenues	$ 48,048	$ 51,705	$ 89,909	$ 94,172
Cost of revenues	32,177	34,026	60,524	61,764
Gross profit	15,871	17,679	29,385	32,408
Operating expenses:
Research and development	6,494	4,898	12,916	9,181
Sales, general, and administrative	8,572	7,232	16,716	13,470
Total operating expenses	15,066	12,130	29,632	22,651
Income (loss) from operations	805	5,549	(247)	9,757
Other income (expense):
Interest income (expense), net	740	(6)	1,490	(225)
Other income (expense), net	(907)	(42)	(87)	34
Income before income taxes	638	5,501	1,156	9,566
Income tax expense	793	848	2,546	1,997
Net income (loss)	(155)	4,653	(1,390)	7,569
Less: Income allocated to participating securities	0	(1,499)	0	(4,415)
Net income (loss) attributable to common stockholders	$ (155)	$ 3,154	$ (1,390)	$ 3,154
Net income (loss) per share, basic (in dollars per share)	$ 0	$ 0.13	$ (0.04)	$ 0.23
Net income (loss) per share, diluted (in dollars per share)	$ 0	$ 0.11	$ (0.04)	$ 0.17
Shares used in per share calculations:
Basic (in shares)	37,065	24,491	36,880	13,761
Diluted (in shares)	37,065	29,756	36,880	18,797

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (155)	$ 4,653	$ (1,390)	$ 7,569
Other comprehensive income (loss):
Foreign currency translation adjustments, net of tax	317	(1,588)	57	(638)
Comprehensive income (loss)	$ 162	$ 3,065	$ (1,333)	$ 6,931

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	IPO	Preferred stock	Preferred stockConvertible preferred stock	Common stock	Common stockIPO	Additional paid-in capital	Additional paid-in capitalIPO	Accumulated other comprehensive income (loss)	Accumulated deficit
Stock outstanding, beginning balance (in shares) at Dec. 31, 2017				24,642,000
Stock, beginning balance at Dec. 31, 2017				$ 12
Common stock, shares outstanding, beginning balance (in shares) at Dec. 31, 2017					2,979,000
Common stock, beginning balance at Dec. 31, 2017	$ 61,283				$ 2		$ 180,657		$ (719)	$ (118,669)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	7,569									7,569
Proceeds from initial public offering (in shares)						6,900,000
Proceeds from initial public offering		$ 110,400				$ 1		$ 110,399
Conversion of convertible preferred stock to common stock (in shares)				(24,642,000)	24,642,000
Conversion of convertible preferred stock to common stock	0			$ (12)	$ 12
Exercise of warrants for common stock (in shares)					15,000
Exercise of warrants for common stock	0
Exercise of stock options (in shares)					256,000
Exercise of stock options	123						123
Stock-based compensation	968						968
Deferred offering costs	(9,469)						(9,469)
Cumulative translation adjustment	(638)								(638)
Stock outstanding, ending balance (in shares) at Jun. 30, 2018				0
Stock, ending balance at Jun. 30, 2018				$ 0
Common stock, shares outstanding, ending balance (in shares) at Jun. 30, 2018					34,792,000
Common stock, ending balance at Jun. 30, 2018	170,236				$ 15		282,678		(1,357)	(111,100)
Stock outstanding, beginning balance (in shares) at Mar. 31, 2018				24,642,000
Stock, beginning balance at Mar. 31, 2018				$ 12
Common stock, shares outstanding, beginning balance (in shares) at Mar. 31, 2018					3,056,000
Common stock, beginning balance at Mar. 31, 2018	64,585				$ 2		180,093		231	(115,753)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	4,653									4,653
Proceeds from initial public offering (in shares)						6,900,000
Proceeds from initial public offering		$ 110,400				$ 1		$ 110,399
Conversion of convertible preferred stock to common stock (in shares)				(24,642,000)	24,642,000
Conversion of convertible preferred stock to common stock	0			$ (12)	$ 12
Exercise of warrants for common stock (in shares)					15,000
Exercise of warrants for common stock	0
Exercise of stock options (in shares)					179,000
Exercise of stock options	62						62
Stock-based compensation	806						806
Deferred offering costs	(8,682)						(8,682)
Cumulative translation adjustment	(1,588)								(1,588)
Stock outstanding, ending balance (in shares) at Jun. 30, 2018				0
Stock, ending balance at Jun. 30, 2018				$ 0
Common stock, shares outstanding, ending balance (in shares) at Jun. 30, 2018					34,792,000
Common stock, ending balance at Jun. 30, 2018	$ 170,236				$ 15		282,678		(1,357)	(111,100)
Stock outstanding, beginning balance (in shares) at Dec. 31, 2018	0		0
Stock, beginning balance at Dec. 31, 2018			$ 0
Common stock, shares outstanding, beginning balance (in shares) at Dec. 31, 2018	36,705,000				36,705,000
Common stock, beginning balance at Dec. 31, 2018	$ 217,783				$ 15		324,656		(2,157)	(104,731)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ (1,390)									(1,390)
Exercise of stock options (in shares)	518,000				518,000
Exercise of stock options	$ 915						915
Issuance of common stock pursuant to vesting of restricted stock awards and units, net of stock withheld for tax (in shares)					399,000
Issuance of common stock pursuant to vesting of restricted stock awards and units, net of stock withheld for tax	$ (480)						(480)
Issuance of common stock under the Employee Stock Purchase Plan (in shares)	43,000				43,000
Issuance of common stock under the Employee Stock Purchase Plan	$ 762						762
Stock-based compensation	4,290						4,129			161
Cumulative translation adjustment	$ 57								57
Stock outstanding, ending balance (in shares) at Jun. 30, 2019	0		0
Stock, ending balance at Jun. 30, 2019			$ 0
Common stock, shares outstanding, ending balance (in shares) at Jun. 30, 2019	37,665,000				37,665,000
Common stock, ending balance at Jun. 30, 2019	$ 221,937				$ 15		329,982		(2,100)	(105,960)
Stock outstanding, beginning balance (in shares) at Mar. 31, 2019			0
Stock, beginning balance at Mar. 31, 2019			$ 0
Common stock, shares outstanding, beginning balance (in shares) at Mar. 31, 2019					36,906,000
Common stock, beginning balance at Mar. 31, 2019	218,663				$ 15		326,870		(2,417)	(105,805)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(155)									(155)
Exercise of stock options (in shares)					317,000
Exercise of stock options	449						449
Issuance of common stock pursuant to vesting of restricted stock awards and units, net of stock withheld for tax (in shares)					399,000
Issuance of common stock pursuant to vesting of restricted stock awards and units, net of stock withheld for tax	(480)						(480)
Issuance of common stock under the Employee Stock Purchase Plan (in shares)					43,000
Issuance of common stock under the Employee Stock Purchase Plan	762						762
Stock-based compensation	2,381						2,381			0
Cumulative translation adjustment	$ 317								317
Stock outstanding, ending balance (in shares) at Jun. 30, 2019	0		0
Stock, ending balance at Jun. 30, 2019			$ 0
Common stock, shares outstanding, ending balance (in shares) at Jun. 30, 2019	37,665,000				37,665,000
Common stock, ending balance at Jun. 30, 2019	$ 221,937				$ 15		$ 329,982		$ (2,100)	$ (105,960)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash flows from operating activities:
Net income (loss)	$ (1,390)	$ 7,569
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Depreciation	3,205	2,936
Amortization	1,276	1,182
Provision for losses on accounts receivable	33	183
Stock-based compensation	4,290	968
Loss on disposal of property and equipment	5	11
Changes in operating assets and liabilities:
Accounts receivable, net	(4,334)	(8,711)
Inventory	(6,987)	(5,644)
Prepaid expenses and other current assets	3,192	(3,458)
Other assets	(1,800)	(1,226)
Accounts payable	1,111	3,539
Accrued and other long-term liabilities	(25)	(736)
Deferred revenues	(141)	502
Non-current income taxes payable	382	540
Net cash used in operating activities	(1,183)	(2,345)
Cash flows from investing activities:
Purchases of property, equipment and patents	(6,916)	(5,789)
Proceeds from sale of property and equipment	0	8
Net cash used in investing activities	(6,916)	(5,781)
Cash flows from financing activities:
Principal payments on debt and capital leases	(50)	(74)
Proceeds from public offering, net of offering costs	0	101,486
Proceeds from employee stock plan purchases	762	0
Proceeds from stock option exercises	915	123
Tax payments related to stock award issuances	(480)	0
Net cash provided by financing activities	1,147	101,535
Effect of exchange rate changes on cash	135	(371)
Net increase (decrease) in cash and cash equivalents	(6,817)	93,038
Cash and cash equivalents, beginning of period	149,478	36,687
Cash and cash equivalents, end of period	142,661	129,725
Supplemental disclosures:
Cash paid (received) for interest	(1,552)	506
Cash paid for income taxes	1,393	2,119
Accrued purchases of property, equipment and patents	952	675
Accrued deferred offering costs	$ 0	$ 1,087

Basis of Presentation and New A

Basis of Presentation and New Accounting Pronouncements	6 Months Ended
	Jun. 30, 2019
Accounting Policies [Abstract]
Basis of Presentation and New Accounting Pronouncements	Basis of Presentation and New Accounting Pronouncements Basis of Presentation The accompanying consolidated financial statements of nLIGHT, Inc. and its wholly owned subsidiaries (the "Company") have been prepared in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP") and pursuant to the rules and regulations of the Securities and Exchange Commission ("SEC"). The unaudited financial information reflects, in the opinion of the management, all adjustments necessary for a fair presentation of financial position, results of operations, stockholders’ equity, and cash flows for the interim periods presented. The results reported for the interim period presented are not necessarily indicative of results that may be expected for the full year. These consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto included in our 2018 Annual Report on Form 10-K. Reclassifications Certain immaterial reclassifications were made to the prior period financial statements to conform to the current period presentation. Critical Accounting Policies Other than the adoption of new revenue recognition guidance as described in Note 11, our critical accounting policies have not changed during the three and six months ended June 30, 2019 from those disclosed in our Annual Report on Form 10-K for the year ended December 31, 2018 . New Accounting Pronouncements ASU 2018-07 The Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2018-07, Improvements to Nonemployee Share-Based Payment Accounting (Topic 718) , in June 2018. ASU 2018-07 simplifies the accounting for share-based payments made to nonemployees so the accounting for such payments is substantially the same as those made to employees. The Company adopted ASU 2018-07 on January 1, 2019 using the modified retrospective approach with fair value measurement of unsettled liability-classified nonemployee awards, and recorded a cumulative effect adjustment of $161 thousand to beginning retained earnings. ASU 2016-02, ASU 2018-10 and ASU 2018-11 The FASB issued ASU 2016-02, Leases (Topic 842), in February 2016. ASU 2016-02 requires the recognition of right-of-use ("ROU") assets and lease liabilities on the balance sheet for virtually all leases, other than leases that meet the definition of short-term. ASU 2016-02 was amended in July 2018 by both ASU 2018-10, Codification Improvements to Topic 842, Leases , and ASU 2018-11, Leases (Topic 842): Targeted Improvements . As initially issued, the standard required lessees, upon adoption, to recognize and measure leases at the beginning of the earliest period presented using a modified retrospective approach, which includes a number of optional practical expedients that entities may elect to apply. As amended, the standard allows an alternative transition method that permits entities to use its effective date as the date of initial application, and not restate comparative prior period financial information. ASU 2016-02, as amended, is effective for annual reporting periods of emerging growth companies beginning after December 15, 2019. The Company expects to implement the provisions of ASU 2016‑02, as amended, as of January 1, 2020 using the alternative modified retrospective transition method. The Company is currently evaluating the impact on its consolidated financial statements and cannot reasonably estimate the quantitative impact on its financial statements at this time. However, the Company expects the primary impact will be the recognition, on a discounted basis, of its minimum commitments under non-cancelable operating leases on its consolidated balance sheets, resulting in the recording of new ROU assets and lease obligations. In addition, the Company also expects this ASU, as amended, to have significant additional disclosure requirements. The standard provides several optional practical expedients in transition. The Company expects to elect the package of practical expedients, which permits us to not reassess, under the new standard, our prior conclusions about lease identification, lease classification and initial direct costs. Additionally, the Company does not expect to elect the use-of-hindsight or the practical expedient pertaining to land easements, the latter not being applicable to nLIGHT. The new standard also provides practical expedients for an entity’s ongoing accounting. Further, the Company expects to elect the short-term lease recognition exemption as well as the practical expedient to not separate lease and non-lease components for all its leases.

Concentrations of Credit and Ot

Concentrations of Credit and Other Risks	6 Months Ended
	Jun. 30, 2019
Risks and Uncertainties [Abstract]
Concentrations of Credit and Other Risks	Concentrations of Credit and Other Risks The following customers accounted for 10% or more of our revenues for the periods presented: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Quick Laser Technology Co., Ltd. 10% 19% —% 16% Raytheon Company 10% —% 10% —% Financial instruments that potentially expose the Company to concentrations of credit risk consist principally of accounts receivable. As of June 30, 2019 and December 31, 2018 , one customer accounted for 22% and 17% of gross accounts receivable, respectively. No other customers accounted for 10% or more of gross accounts receivable in either of these periods.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	6 Months Ended
	Jun. 30, 2019
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	Fair Value of Financial Instruments The Company's fair value hierarchy for its financial instruments consists of cash equivalents as follows (in thousands): June 30, 2019 Level 1 Level 2 Level 3 Total Money market securities $ 124,510 $ — $ — $ 124,510 Commercial paper 586 — — 586 Total $ 125,096 $ — $ — $ 125,096 December 31, 2018 Level 1 Level 2 Level 3 Total Money market securities $ 123,121 $ — $ — $ 123,121 Commercial paper 299 — — 299 Total $ 123,420 $ — $ — $ 123,420 There have been no other material changes to the financial instruments as previously disclosed in the Company's Annual Report on Form 10-K for the year ended December 31, 2018 .

Inventory

Inventory	6 Months Ended
	Jun. 30, 2019
Inventory Disclosure [Abstract]
Inventory	Inventory Inventory is stated at the lower of average cost and net realizable value. Inventory consisted of the following (in thousands): June 30, 2019 December 31, 2018 Raw materials $ 15,514 $ 14,174 Work in process and semi-finished goods 15,772 12,807 Finished goods 10,999 8,348 $ 42,285 $ 35,329

Other Assets

Other Assets	6 Months Ended
	Jun. 30, 2019
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Other Assets	Other Assets Other assets consisted of the following (in thousands): June 30, 2019 December 31, 2018 Demonstration assets, net $ 1,752 $ 1,982 Deferred tax assets, net 3,114 3,114 Other 1,910 878 $ 6,776 $ 5,974 Demonstration (demo) assets are equipment that is used for demonstration and other purposes with existing and prospective customers. Demo assets are recorded at cost and amortized over an estimated useful life of approximately two years . Amortization expense for demo assets totaled $0.4 million and $0.5 million for the three months ended June 30, 2019 and 2018 , respectively and $0.9 million and $0.9 million for the six months ended June 30, 2019 and 2018 , respectively.

Accrued Liabilities

Accrued Liabilities	6 Months Ended
	Jun. 30, 2019
Payables and Accruals [Abstract]
Accrued Liabilities	Accrued Liabilities Accrued liabilities consist of the following (in thousands): June 30, 2019 December 31, 2018 Accrued payroll and benefits $ 6,710 $ 6,474 Product warranty, current 2,002 2,669 Income tax payable 486 258 Other accrued expenses 1,495 1,307 $ 10,693 $ 10,708

Product Warranties

Product Warranties	6 Months Ended
	Jun. 30, 2019
Guarantees and Product Warranties [Abstract]
Product Warranties	Product Warranties We offer warranties on certain products and record a liability for the estimated future costs associated with warranty claims at the time revenue is recognized. The warranty liability is based on historical experience, any specifically identified failures, and our estimate of future costs. Product warranty liability activity for the six months ended June 30, 2019 and 2018 was as follows (in thousands): Six Months Ended June 30, 2019 2018 Product warranty liability, beginning $ 4,555 $ 4,186 Warranty charges incurred, net (1,161 ) (1,335 ) Provision for warranty charges, net of adjustments 249 1,773 Product warranty liability, ending $ 3,643 $ 4,624 Less: current portion of product warranty liability (2,002 ) (3,480 ) Non-current portion of product warranty liability $ 1,641 $ 1,144

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Income Tax Provision To calculate the interim tax provision, at the end of each interim period the Company estimates the annual effective tax rate and applies that to its ordinary quarterly earnings. The effect of changes in the enacted tax laws or rates is recognized in the interim period in which the change occurs. The computation of the annual estimated effective tax rate at each interim period requires certain estimates and judgments including, but not limited to, the expected operating income for the year, projections of the proportion of income earned and taxed in foreign jurisdictions, permanent differences between book and tax amounts, and the likelihood of recovering deferred tax assets generated in the current year. The accounting estimates used to compute the provision for income taxes may change as new events occur, additional information is obtained, or the tax environment changes. The Company’s effective tax rate for the three and six months ended June 30, 2019 and 2018 differs from the U.S. statutory rate due to the U.S. valuation allowance, foreign income taxed at local statutory rates, and accrued withholding taxes. The increase in the effective tax rate for three and six months ended June 30, 2019 relative to 2018 is primarily due to decreased profitability within the U.S. entity as the Company maintains a full valuation allowance against the U.S. deferred tax assets. In fiscal year to date 2019 , the Company reported U.S. pre-tax losses, consistent with prior fiscal years to date within this decade, other than 2018. The Company has not yet been able to establish a sustained level of profitability in the U.S. or other sufficient significant positive evidence to conclude that its U.S. deferred tax assets are more likely than not to be realized. Therefore, the Company continues to maintain a valuation allowance against its U.S. deferred tax assets. It is reasonably possible that by the end of 2019 , the Company will establish a sustained level of profitability in the U.S. As a result, it may reverse a significant portion of the valuation allowance recorded against its U.S. deferred tax assets. The reversal would result in an income tax benefit for the three months and the year ending December 31, 2019 .

Stockholders' Equity and Stock-

Stockholders' Equity and Stock-Based Compensation	6 Months Ended
	Jun. 30, 2019
Equity [Abstract]
Stockholders' Equity and Stock-Based Compensation	Stockholders' Equity and Stock-Based Compensation Restricted Stock Awards and Units Restricted stock award ("RSA") and restricted stock unit ("RSU") activity under our equity incentive plan was as follows (in thousands, except weighted average grant date fair values): Number of Restricted Stock Awards Weighted-Average Grant Date Fair Value RSAs at December 31, 2018 115 $ 37.15 Awards granted 340 18.69 Awards vested (11 ) 37.15 RSAs at June 30, 2019 444 $ 23.02 Number of Restricted Stock Units Weighted-Average Grant Date Fair Value RSUs at December 31, 2018 557 $ 30.31 Awards granted 1,003 18.95 Awards vested (86 ) 33.44 Awards forfeited (12 ) 33.41 RSUs at June 30, 2019 1,462 $ 22.30 The total fair value of RSAs and RSUs vested during the six months ended June 30, 2019 was $0.4 million and $2.9 million , respectively. Awards outstanding as of June 30, 2019 include 0.5 million performance-based awards that will vest upon meeting certain performance criteria. Stock Options The following table summarizes the Company’s stock option activity during the six months ended June 30, 2019 (in thousands, except weighted average exercise prices): Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term (Years) Aggregate Intrinsic Value Outstanding, December 31, 2018 5,171 $1.60 7.2 $83,700 Options exercised (518 ) $1.77 Options canceled (38 ) $3.06 Outstanding, June 30, 2019 4,615 $1.56 6.7 $81,400 Options exercisable at June 30, 2019 2,997 $1.01 6.2 $54,532 Options vested as of June 30, 2019 and expected to vest after June 30, 2019 4,615 $1.56 6.7 $81,400 Total intrinsic value of options exercised for the six months ended June 30, 2019 and 2018 was $10.4 million and $1.9 million , respectively. The Company received proceeds of $0.9 million and $0.1 million from the exercise of options for the six months ended June 30, 2019 and 2018 , respectively. Employee Stock Purchase Plan Information related to activity under our Employee Stock Purchase Plan ("ESPP") program was as follows (in thousands, except weighted average per share prices): Six Months Ended June 30, 2019 Shares issued 43 Weighted average per share purchase price $ 17.91 Weighted average per share discount from the fair value of our common stock on date of issuance $ 3.16 Stock-Based Compensation Total stock-based compensation expense was included in our consolidated statements of income as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Cost of revenues $ 267 $ 62 $ 476 $ 84 Research and development 711 200 1,269 225 Sales, general and administrative 1,403 544 2,545 659 $ 2,381 $ 806 $ 4,290 $ 968 Unrecognized Compensation Costs As of June 30, 2019 , total unrecognized stock-based compensation related to outstanding, but unvested stock awards was $40.4 million , which will be recognized over the weighted average remaining vesting period of 3.3 years.

Net Income (Loss) per Share

Net Income (Loss) per Share	6 Months Ended
	Jun. 30, 2019
Earnings Per Share [Abstract]
Net Income (Loss) per Share	Net Income (Loss) per Share The following table sets forth the calculation of basic and diluted net income (loss) per share attributable to common stockholders during the periods presented (in thousands, except per share amounts): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Numerator: Net income (loss) $ (155 ) $ 4,653 $ (1,390 ) $ 7,569 Participating securities: Income allocated to participating securities — (1,499 ) — (4,415 ) Net income (loss) attributable to common stockholders (155 ) 3,154 (1,390 ) 3,154 Denominator: Weighted-average shares, basic 37,065 24,491 36,880 13,761 Dilutive effect of warrants — 155 — 137 Dilutive effect of restricted stock units and awards — 5 — 1 Dilutive effect of common stock options — 5,105 — 4,898 Weighted-average common shares outstanding, diluted 37,065 29,756 36,880 18,797 Net income (loss) per share attributable to common stockholders: Basic $ — $ 0.13 $ (0.04 ) $ 0.23 Diluted $ — $ 0.11 $ (0.04 ) $ 0.17 The following potentially dilutive shares of restricted stock awards and units, employee stock purchase plan, and stock options were not included in the calculation of diluted shares above as the effect would have been anti‑dilutive (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Restricted stock units and awards 1,906 541 1,906 541 Employee stock purchase plan 40 — 75 — Common stock options 4,615 — 4,615 — Total 6,561 541 6,596 541

Revenue

Revenue	6 Months Ended
	Jun. 30, 2019
Revenue from Contract with Customer [Abstract]
Revenue	Revenue Adoption of ASC 606 The Company adopted ASC 606 “ Revenue from Contracts with Customers” using the cumulative effect method with a date of initial application of January 1, 2019. Therefore, the comparative period information has not been adjusted and continues to be reported under ASC 605 “ Revenue Recognition. ” The impact of adoption was immaterial, and the Company expects the impact of the adoption of the new standard to be immaterial to the consolidated financial statements on an ongoing basis. A majority of the Company's revenue continues to be recognized at a point in time when control transfers based on the terms of the underlying contract. Revenue Recognition Revenue is recognized when transfer of control to the customer occurs in an amount reflecting the consideration to which the Company expects to be entitled. In order to achieve this core principle, the Company applies the following five step approach: (1) identify the contract with a customer, (2) identify the performance obligations in the contract, (3) determine the transaction price, (4) allocate the transaction price to the performance obligations in the contract, and (5) recognize revenue when a performance obligation is satisfied. The Company considers customer purchase orders, which in some cases are governed by master sales agreements, to be the contracts with a customer. As part of its consideration of the contract, the Company evaluates certain factors including the customer's ability to pay (or credit risk). For each contract, the Company considers the promise to transfer products, each of which is distinct, as the identified performance obligations. As the Company's standard payment terms are less than one year, the Company has elected the practical expedient under ASC 606-10-32-18 to not assess whether a contract has a significant financing component. Payment terms in excess of one year are evaluated as they occur. The Company allocates the transaction price to each distinct product based on its relative standalone selling price. Master sales agreements or purchase orders from customers could include a single product or multiple products. Regardless, the contracted price with the customer is agreed to at the individual product level outlined in the customer contract or purchase order. The Company does not bundle prices; however, it does negotiate with customers on pricing for the same products based on a variety of factors (e.g., level of contractual volume). The Company has concluded that the prices negotiated with each individual customer are representative of the stand-alone selling price of the product. Revenue is recognized when control of the product is transferred to the customer (i.e., when the Company's performance obligation is satisfied), which typically occurs at shipment or delivery, depending on shipping terms. The Company often receives orders with multiple delivery dates that may extend across several reporting periods. The Company allocates the transaction price of the contract to each delivery based on the product standalone selling price. The Company invoices for each scheduled delivery upon shipment or delivery and recognizes revenues for such delivery at that point, assuming transfer of control has occurred. As scheduled delivery dates are generally within one year, under the optional exemption provided by ASC 606-10-50-14 revenues allocated to future shipments of partially completed contracts are not disclosed. Rights of return generally are not included in customer contracts. Accordingly, product revenue is recognized upon shipment or delivery, as applicable, and transfer of control. Rights of return are evaluated as they occur. As part of its adoption of the new revenue standard, the Company has elected to account for shipping and handling as fulfillment activities and record them in cost of sales. The election of this practical expedient results in accounting treatment consistent with the Company’s historical accounting policies and therefore, this election does not impact the comparability of the financial statements. Revenue Recognition at a Point in Time - Revenues recognized at a point in time consist of sales of semiconductor lasers, fiber lasers and other related products. Revenue Recognition over Time - Revenues recognized over time generally consist of arrangements for goods and services that are structured based on the Company’s costs. Revenue for these arrangements is recognized as control transfers, which occurs as the work is performed. Billing under these arrangements generally occurs within one month after the work is completed. The following tables represent a disaggregation of revenue from contracts with customers for the periods presented (in thousands): Sales by End Market Three Months Ended June 30, Six Months Ended June 30, 2019 2019 Industrial $ 20,920 $ 39,044 Microfabrication 18,094 32,627 Aerospace and Defense 9,034 18,238 $ 48,048 $ 89,909 Sales by Geography Three Months Ended June 30, Six Months Ended June 30, 2019 2019 North America $ 18,142 $ 33,912 China 18,201 31,854 Rest of World 11,705 24,143 $ 48,048 $ 89,909 Contract balances - The timing of revenue recognition may differ from the timing of invoicing to customers. Accounts receivable is recorded at the invoiced amount, net of an allowance for doubtful accounts. A receivable is recognized in the period we deliver goods or provide services or when our right to consideration is unconditional. A contract asset is recorded when we have performed under the contract but our right to consideration is conditional on something other than the passage of time. Contract assets as of June 30, 2019 were $0.1 million and are reported on the consolidated balance sheets as a component of prepaid expenses and other current assets. Contract liabilities include payments received in advance of performance under a contract and are satisfied as the associated revenue is recognized. Contract liabilities are reported on the consolidated balance sheets at the end of each reporting period as a component of deferred revenue. Contract liabilities as of June 30, 2019 were $0.6 million . During the three and six months ended June 30, 2019 , the Company recognized revenue of $0.1 million and $0.7 million , respectively, that was included in the customer advances and deferred revenue balances at the beginning of the periods as the performance obligations under the associated agreements were satisfied during the three and six months ended June 30, 2019 .

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Contractual Commitments and Purchase Obligations Our purchase obligations and other contractual obligations have not materially changed as of June 30, 2019 from those disclosed in our Annual Report on Form 10-K for the year ended December 31, 2018 . Legal Matters From time to time, we may be subject to legal proceedings and claims in the ordinary course of business. As of June 30, 2019 , and as of the filing of this Quarterly Report on Form 10-Q, we were not involved in any material legal proceedings.

Basis of Presentation and New_2

Basis of Presentation and New Accounting Pronouncements (Policies)	6 Months Ended
	Jun. 30, 2019
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements of nLIGHT, Inc. and its wholly owned subsidiaries (the "Company") have been prepared in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP") and pursuant to the rules and regulations of the Securities and Exchange Commission ("SEC"). The unaudited financial information reflects, in the opinion of the management, all adjustments necessary for a fair presentation of financial position, results of operations, stockholders’ equity, and cash flows for the interim periods presented. The results reported for the interim period presented are not necessarily indicative of results that may be expected for the full year. These consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto included in our 2018 Annual Report on Form 10-K.
New Accounting Pronouncements	New Accounting Pronouncements ASU 2018-07 The Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2018-07, Improvements to Nonemployee Share-Based Payment Accounting (Topic 718) , in June 2018. ASU 2018-07 simplifies the accounting for share-based payments made to nonemployees so the accounting for such payments is substantially the same as those made to employees. The Company adopted ASU 2018-07 on January 1, 2019 using the modified retrospective approach with fair value measurement of unsettled liability-classified nonemployee awards, and recorded a cumulative effect adjustment of $161 thousand to beginning retained earnings. ASU 2016-02, ASU 2018-10 and ASU 2018-11 The FASB issued ASU 2016-02, Leases (Topic 842), in February 2016. ASU 2016-02 requires the recognition of right-of-use ("ROU") assets and lease liabilities on the balance sheet for virtually all leases, other than leases that meet the definition of short-term. ASU 2016-02 was amended in July 2018 by both ASU 2018-10, Codification Improvements to Topic 842, Leases , and ASU 2018-11, Leases (Topic 842): Targeted Improvements . As initially issued, the standard required lessees, upon adoption, to recognize and measure leases at the beginning of the earliest period presented using a modified retrospective approach, which includes a number of optional practical expedients that entities may elect to apply. As amended, the standard allows an alternative transition method that permits entities to use its effective date as the date of initial application, and not restate comparative prior period financial information. ASU 2016-02, as amended, is effective for annual reporting periods of emerging growth companies beginning after December 15, 2019. The Company expects to implement the provisions of ASU 2016‑02, as amended, as of January 1, 2020 using the alternative modified retrospective transition method. The Company is currently evaluating the impact on its consolidated financial statements and cannot reasonably estimate the quantitative impact on its financial statements at this time. However, the Company expects the primary impact will be the recognition, on a discounted basis, of its minimum commitments under non-cancelable operating leases on its consolidated balance sheets, resulting in the recording of new ROU assets and lease obligations. In addition, the Company also expects this ASU, as amended, to have significant additional disclosure requirements. The standard provides several optional practical expedients in transition. The Company expects to elect the package of practical expedients, which permits us to not reassess, under the new standard, our prior conclusions about lease identification, lease classification and initial direct costs. Additionally, the Company does not expect to elect the use-of-hindsight or the practical expedient pertaining to land easements, the latter not being applicable to nLIGHT. The new standard also provides practical expedients for an entity’s ongoing accounting. Further, the Company expects to elect the short-term lease recognition exemption as well as the practical expedient to not separate lease and non-lease components for all its leases.
Inventory	Inventory is stated at the lower of average cost and net realizable value.
Product Warranties	We offer warranties on certain products and record a liability for the estimated future costs associated with warranty claims at the time revenue is recognized. The warranty liability is based on historical experience, any specifically identified failures, and our estimate of future costs.
Income Taxes	To calculate the interim tax provision, at the end of each interim period the Company estimates the annual effective tax rate and applies that to its ordinary quarterly earnings. The effect of changes in the enacted tax laws or rates is recognized in the interim period in which the change occurs. The computation of the annual estimated effective tax rate at each interim period requires certain estimates and judgments including, but not limited to, the expected operating income for the year, projections of the proportion of income earned and taxed in foreign jurisdictions, permanent differences between book and tax amounts, and the likelihood of recovering deferred tax assets generated in the current year. The accounting estimates used to compute the provision for income taxes may change as new events occur, additional information is obtained, or the tax environment changes.
Revenue Recognition	Revenue Recognition Revenue is recognized when transfer of control to the customer occurs in an amount reflecting the consideration to which the Company expects to be entitled. In order to achieve this core principle, the Company applies the following five step approach: (1) identify the contract with a customer, (2) identify the performance obligations in the contract, (3) determine the transaction price, (4) allocate the transaction price to the performance obligations in the contract, and (5) recognize revenue when a performance obligation is satisfied. The Company considers customer purchase orders, which in some cases are governed by master sales agreements, to be the contracts with a customer. As part of its consideration of the contract, the Company evaluates certain factors including the customer's ability to pay (or credit risk). For each contract, the Company considers the promise to transfer products, each of which is distinct, as the identified performance obligations. As the Company's standard payment terms are less than one year, the Company has elected the practical expedient under ASC 606-10-32-18 to not assess whether a contract has a significant financing component. Payment terms in excess of one year are evaluated as they occur. The Company allocates the transaction price to each distinct product based on its relative standalone selling price. Master sales agreements or purchase orders from customers could include a single product or multiple products. Regardless, the contracted price with the customer is agreed to at the individual product level outlined in the customer contract or purchase order. The Company does not bundle prices; however, it does negotiate with customers on pricing for the same products based on a variety of factors (e.g., level of contractual volume). The Company has concluded that the prices negotiated with each individual customer are representative of the stand-alone selling price of the product. Revenue is recognized when control of the product is transferred to the customer (i.e., when the Company's performance obligation is satisfied), which typically occurs at shipment or delivery, depending on shipping terms. The Company often receives orders with multiple delivery dates that may extend across several reporting periods. The Company allocates the transaction price of the contract to each delivery based on the product standalone selling price. The Company invoices for each scheduled delivery upon shipment or delivery and recognizes revenues for such delivery at that point, assuming transfer of control has occurred. As scheduled delivery dates are generally within one year, under the optional exemption provided by ASC 606-10-50-14 revenues allocated to future shipments of partially completed contracts are not disclosed. Rights of return generally are not included in customer contracts. Accordingly, product revenue is recognized upon shipment or delivery, as applicable, and transfer of control. Rights of return are evaluated as they occur. As part of its adoption of the new revenue standard, the Company has elected to account for shipping and handling as fulfillment activities and record them in cost of sales. The election of this practical expedient results in accounting treatment consistent with the Company’s historical accounting policies and therefore, this election does not impact the comparability of the financial statements. Revenue Recognition at a Point in Time - Revenues recognized at a point in time consist of sales of semiconductor lasers, fiber lasers and other related products. Revenue Recognition over Time - Revenues recognized over time generally consist of arrangements for goods and services that are structured based on the Company’s costs. Revenue for these arrangements is recognized as control transfers, which occurs as the work is performed. Billing under these arrangements generally occurs within one month after the work is completed.

Concentrations of Credit and _2

Concentrations of Credit and Other Risks (Tables)	6 Months Ended
	Jun. 30, 2019
Risks and Uncertainties [Abstract]
Schedule of concentration of credit	The following customers accounted for 10% or more of our revenues for the periods presented: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Quick Laser Technology Co., Ltd. 10% 19% —% 16% Raytheon Company 10% —% 10% —%

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	6 Months Ended
	Jun. 30, 2019
Fair Value Disclosures [Abstract]
Schedule of fair value hierarchy for its cash equivalents	The Company's fair value hierarchy for its financial instruments consists of cash equivalents as follows (in thousands): June 30, 2019 Level 1 Level 2 Level 3 Total Money market securities $ 124,510 $ — $ — $ 124,510 Commercial paper 586 — — 586 Total $ 125,096 $ — $ — $ 125,096 December 31, 2018 Level 1 Level 2 Level 3 Total Money market securities $ 123,121 $ — $ — $ 123,121 Commercial paper 299 — — 299 Total $ 123,420 $ — $ — $ 123,420

Inventory (Tables)

Inventory (Tables)	6 Months Ended
	Jun. 30, 2019
Inventory Disclosure [Abstract]
Schedule of components of inventory	Inventory consisted of the following (in thousands): June 30, 2019 December 31, 2018 Raw materials $ 15,514 $ 14,174 Work in process and semi-finished goods 15,772 12,807 Finished goods 10,999 8,348 $ 42,285 $ 35,329

Other Assets (Tables)

Other Assets (Tables)	6 Months Ended
	Jun. 30, 2019
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of other assets	Other assets consisted of the following (in thousands): June 30, 2019 December 31, 2018 Demonstration assets, net $ 1,752 $ 1,982 Deferred tax assets, net 3,114 3,114 Other 1,910 878 $ 6,776 $ 5,974

Accrued Liabilities (Tables)

Accrued Liabilities (Tables)	6 Months Ended
	Jun. 30, 2019
Payables and Accruals [Abstract]
Summary of accrued liabilities	Accrued liabilities consist of the following (in thousands): June 30, 2019 December 31, 2018 Accrued payroll and benefits $ 6,710 $ 6,474 Product warranty, current 2,002 2,669 Income tax payable 486 258 Other accrued expenses 1,495 1,307 $ 10,693 $ 10,708

Product Warranties (Tables)

Product Warranties (Tables)	6 Months Ended
	Jun. 30, 2019
Guarantees and Product Warranties [Abstract]
Reconciliation of the changes in the aggregate product warranty liability	Product warranty liability activity for the six months ended June 30, 2019 and 2018 was as follows (in thousands): Six Months Ended June 30, 2019 2018 Product warranty liability, beginning $ 4,555 $ 4,186 Warranty charges incurred, net (1,161 ) (1,335 ) Provision for warranty charges, net of adjustments 249 1,773 Product warranty liability, ending $ 3,643 $ 4,624 Less: current portion of product warranty liability (2,002 ) (3,480 ) Non-current portion of product warranty liability $ 1,641 $ 1,144

Stockholders' Equity and Stoc_2

Stockholders' Equity and Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2019
Equity [Abstract]
Summary of restricted stock awards and units	Restricted stock award ("RSA") and restricted stock unit ("RSU") activity under our equity incentive plan was as follows (in thousands, except weighted average grant date fair values): Number of Restricted Stock Awards Weighted-Average Grant Date Fair Value RSAs at December 31, 2018 115 $ 37.15 Awards granted 340 18.69 Awards vested (11 ) 37.15 RSAs at June 30, 2019 444 $ 23.02 Number of Restricted Stock Units Weighted-Average Grant Date Fair Value RSUs at December 31, 2018 557 $ 30.31 Awards granted 1,003 18.95 Awards vested (86 ) 33.44 Awards forfeited (12 ) 33.41 RSUs at June 30, 2019 1,462 $ 22.30
Summary of stock option activity	The following table summarizes the Company’s stock option activity during the six months ended June 30, 2019 (in thousands, except weighted average exercise prices): Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term (Years) Aggregate Intrinsic Value Outstanding, December 31, 2018 5,171 $1.60 7.2 $83,700 Options exercised (518 ) $1.77 Options canceled (38 ) $3.06 Outstanding, June 30, 2019 4,615 $1.56 6.7 $81,400 Options exercisable at June 30, 2019 2,997 $1.01 6.2 $54,532 Options vested as of June 30, 2019 and expected to vest after June 30, 2019 4,615 $1.56 6.7 $81,400
Schedule of Employee Stock Purchase Plan	Information related to activity under our Employee Stock Purchase Plan ("ESPP") program was as follows (in thousands, except weighted average per share prices): Six Months Ended June 30, 2019 Shares issued 43 Weighted average per share purchase price $ 17.91 Weighted average per share discount from the fair value of our common stock on date of issuance $ 3.16
Schedule of stock-based compensation expense	Total stock-based compensation expense was included in our consolidated statements of income as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Cost of revenues $ 267 $ 62 $ 476 $ 84 Research and development 711 200 1,269 225 Sales, general and administrative 1,403 544 2,545 659 $ 2,381 $ 806 $ 4,290 $ 968

Net Income (Loss) per Share (Ta

Net Income (Loss) per Share (Tables)	6 Months Ended
	Jun. 30, 2019
Earnings Per Share [Abstract]
Schedule of basic and diluted net income (loss) per share	The following table sets forth the calculation of basic and diluted net income (loss) per share attributable to common stockholders during the periods presented (in thousands, except per share amounts): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Numerator: Net income (loss) $ (155 ) $ 4,653 $ (1,390 ) $ 7,569 Participating securities: Income allocated to participating securities — (1,499 ) — (4,415 ) Net income (loss) attributable to common stockholders (155 ) 3,154 (1,390 ) 3,154 Denominator: Weighted-average shares, basic 37,065 24,491 36,880 13,761 Dilutive effect of warrants — 155 — 137 Dilutive effect of restricted stock units and awards — 5 — 1 Dilutive effect of common stock options — 5,105 — 4,898 Weighted-average common shares outstanding, diluted 37,065 29,756 36,880 18,797 Net income (loss) per share attributable to common stockholders: Basic $ — $ 0.13 $ (0.04 ) $ 0.23 Diluted $ — $ 0.11 $ (0.04 ) $ 0.17
Schedule of potentially dilutive shares not included in calculation of diluted shares	The following potentially dilutive shares of restricted stock awards and units, employee stock purchase plan, and stock options were not included in the calculation of diluted shares above as the effect would have been anti‑dilutive (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Restricted stock units and awards 1,906 541 1,906 541 Employee stock purchase plan 40 — 75 — Common stock options 4,615 — 4,615 — Total 6,561 541 6,596 541

Revenue (Tables)

Revenue (Tables)	6 Months Ended
	Jun. 30, 2019
Revenue from Contract with Customer [Abstract]
Schedule of sales by end market	The following tables represent a disaggregation of revenue from contracts with customers for the periods presented (in thousands): Sales by End Market Three Months Ended June 30, Six Months Ended June 30, 2019 2019 Industrial $ 20,920 $ 39,044 Microfabrication 18,094 32,627 Aerospace and Defense 9,034 18,238 $ 48,048 $ 89,909
Schedule of sales by geography	Sales by Geography Three Months Ended June 30, Six Months Ended June 30, 2019 2019 North America $ 18,142 $ 33,912 China 18,201 31,854 Rest of World 11,705 24,143 $ 48,048 $ 89,909

Basis of Presentation and New_3

Basis of Presentation and New Accounting Pronouncements (Details) $ in Thousands	Jan. 01, 2019USD ($)
Accounting Standards Update 2018-07
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment	$ 161

Concentrations of Credit and _3

Concentrations of Credit and Other Risks (Details) - Customer concentration risk	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Sales revenue | Quick Laser Technology Co., Ltd.
Concentration Risk [Line Items]
Concentration risk, percentage	10.20%	18.70%	0.00%	16.00%
Sales revenue | Raytheon Company
Concentration Risk [Line Items]
Concentration risk, percentage	9.90%	0.00%	10.40%	0.00%
Accounts receivable | One customer
Concentration Risk [Line Items]
Concentration risk, percentage			22.20%		16.60%

Fair Value of Financial Instr_3

Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, fair value	$ 125,096	$ 123,420
Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, fair value	125,096	123,420
Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, fair value	0	0
Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, fair value	0	0
Money market securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, fair value	124,510	123,121
Money market securities | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, fair value	124,510	123,121
Money market securities | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, fair value	0	0
Money market securities | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, fair value	0	0
Commercial paper
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, fair value	586	299
Commercial paper | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, fair value	586	299
Commercial paper | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, fair value	0	0
Commercial paper | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, fair value	$ 0	$ 0

Inventory (Details)

Inventory (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Inventory Disclosure [Abstract]
Raw materials	$ 15,514	$ 14,174
Work in process and semi-finished goods	15,772	12,807
Finished goods	10,999	8,348
Inventory	$ 42,285	$ 35,329

Other Assets (Details)

Other Assets (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Other Assets, Noncurrent Disclosure [Abstract]
Demonstration assets, net	$ 1,752		$ 1,752		$ 1,982
Deferred tax assets, net	3,114		3,114		3,114
Other	1,910		1,910		878
Other assets	6,776		$ 6,776		$ 5,974
Useful life of demonstration assets			2 years
Amortization expense for demonstration assets	$ 400	$ 500	$ 900	$ 900

Accrued Liabilities (Details)

Accrued Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Payables and Accruals [Abstract]
Accrued payroll and benefits	$ 6,710	$ 6,474
Product warranty, current	2,002	2,669
Income tax payable	486	258
Other accrued expenses	1,495	1,307
Total accrued liabilities	$ 10,693	$ 10,708

Product Warranties (Details)

Product Warranties (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Movement in Standard Product Warranty Accrual [Roll Forward]
Product warranty liability, beginning	$ 4,555	$ 4,186
Warranty charges incurred, net	(1,161)	(1,335)
Provision for warranty charges, net of adjustments	249	1,773
Product warranty liability, ending	3,643	4,624
Less: current portion of product warranty liability	(2,002)	(3,480)
Non-current portion of product warranty liability	$ 1,641	$ 1,144

Stockholders' Equity and Stoc_3

Stockholders' Equity and Stock-Based Compensation - Summary of Restricted Stock Award and Restricted Stock Unit Activity (Details) shares in Thousands	6 Months Ended
	Jun. 30, 2019$ / sharesshares
Restricted stock awards
Number of restricted shares
Balance, beginning (in shares) | shares	115
Granted (in shares) | shares	340
Vested (in shares) | shares	(11)
Balance, ending (in shares) | shares	444
Weighted average exercise price
Balance, beginning (in dollars per share) | $ / shares	$ 37.15
Granted (in dollars per share) | $ / shares	18.69
Vested (in dollars per share) | $ / shares	37.15
Balance, ending (in dollars per share) | $ / shares	$ 23.02
Restricted stock units
Number of restricted shares
Balance, beginning (in shares) | shares	557
Granted (in shares) | shares	1,003
Vested (in shares) | shares	(86)
Forfeited (in shares) | shares	(12)
Balance, ending (in shares) | shares	1,462
Weighted average exercise price
Balance, beginning (in dollars per share) | $ / shares	$ 30.31
Granted (in dollars per share) | $ / shares	18.95
Vested (in dollars per share) | $ / shares	33.44
Forfeited (in dollars per share) | $ / shares	33.41
Balance, ending (in dollars per share) | $ / shares	$ 22.30

Stockholders' Equity and Stoc_4

Stockholders' Equity and Stock-Based Compensation - Narrative (Details) - USD ($) shares in Thousands, $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Intrinsic value of options exercised	$ 10,400	$ 1,900
Proceeds from the exercise of options	915	$ 123
Unrecognized expense	$ 40,400
Average expected recognition period (years)	3 years 3 months 18 days
Restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested, fair value	$ 400
Awards outstanding (in shares)	444		115
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested, fair value	$ 2,900
Awards outstanding (in shares)	1,462		557
Performance restricted stock awards and performance restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards outstanding (in shares)	500

Stockholders' Equity and Stoc_5

Stockholders' Equity and Stock-Based Compensation - Summary of Stock Option Activity (Details) $ / shares in Units, shares in Thousands, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2019USD ($)$ / sharesshares	Dec. 31, 2018USD ($)$ / sharesshares
Number of shares
Outstanding, beginning of period (in shares) | shares	5,171
Options exercised (in shares) | shares	(518)
Options canceled (in shares) | shares	(38)
Outstanding, end of period (in shares) | shares	4,615	5,171
Weighted average exercise price
Outstanding, beginning of period (in dollars per share) | $ / shares	$ 1.60
Options exercised (in dollars per share) | $ / shares	1.77
Options canceled (in dollars per share) | $ / shares	3.06
Outstanding, end of period (in dollars per share) | $ / shares	$ 1.56	$ 1.60
Outstanding, Weighted average remaining contractual term (years)	6 years 8 months 22 days	7 years 2 months 12 days
Outstanding, Aggregate intrinsic value | $	$ 81,400	$ 83,700
Options exercisable at end of period
Number of shares | shares	2,997
Weighted average exercise price (in dollars per share) | $ / shares	$ 1.01
Weighted average remaining contractual term (years)	6 years 2 months 27 days
Aggregate intrinsic value | $	$ 54,532
Options vested as of end of period and expected to vest after end of period
Number of shares | shares	4,615
Weighted average exercise price (in dollars per share) | $ / shares	$ 1.56
Weighted average remaining contractual term (years)	6 years 8 months 22 days
Aggregate intrinsic value | $	$ 81,400

Stockholders' Equity and Stoc_6

Stockholders' Equity and Stock-Based Compensation - Employee Stock Purchase Program (Details) shares in Thousands	6 Months Ended
	Jun. 30, 2019$ / sharesshares
Equity [Abstract]
Shares issued (in shares) | shares	43
Weighted average per share purchase price (in dollars per share)	$ 17.91
Weighted average per share discount from the fair value of our common stock on date of issuance (in dollars per share)	$ 3.16

Stockholders' Equity and Stoc_7

Stockholders' Equity and Stock-Based Compensation - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	$ 2,381	$ 806	$ 4,290	$ 968
Cost of revenues
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	267	62	476	84
Research and development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	711	200	1,269	225
Sales, general and administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	$ 1,403	$ 544	$ 2,545	$ 659

Net Income (Loss) per Share - C

Net Income (Loss) per Share - Calculation of Basic and Diluted Net Income (Loss) per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Numerator:
Net income (loss)	$ (155)	$ 4,653	$ (1,390)	$ 7,569
Income allocated to participating securities	0	(1,499)	0	(4,415)
Net income (loss) attributable to common stockholders	$ (155)	$ 3,154	$ (1,390)	$ 3,154
Denominator:
Weighted-average shares, basic (in shares)	37,065	24,491	36,880	13,761
Dilutive effect of warrants (in shares)	0	155	0	137
Weighted-average common shares outstanding, diluted (in shares)	37,065	29,756	36,880	18,797
Net income (loss) per share attributable to common stockholders:
Basic (in dollars per share)	$ 0	$ 0.13	$ (0.04)	$ 0.23
Diluted (in dollars per share)	$ 0	$ 0.11	$ (0.04)	$ 0.17
Restricted stock units and awards
Denominator:
Dilutive effect of share-based payment arrangements (in shares)	0	5	0	1
Common stock options
Denominator:
Dilutive effect of share-based payment arrangements (in shares)	0	5,105	0	4,898

Net Income (Loss) per Share - A

Net Income (Loss) per Share - Antidilutive Securities Excluded from Dilutive Shares (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	6,561	541	6,596	541
Restricted stock units and awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	1,906	541	1,906	541
Employee stock purchase plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	40	0	75	0
Common stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	4,615	0	4,615	0

Revenue - Disaggregation of Rev

Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation of Revenue [Line Items]
Revenues	$ 48,048	$ 51,705	$ 89,909	$ 94,172
North America
Disaggregation of Revenue [Line Items]
Revenues	18,142		33,912
China
Disaggregation of Revenue [Line Items]
Revenues	18,201		31,854
Rest of World
Disaggregation of Revenue [Line Items]
Revenues	11,705		24,143
Industrial
Disaggregation of Revenue [Line Items]
Revenues	20,920		39,044
Microfabrication
Disaggregation of Revenue [Line Items]
Revenues	18,094		32,627
Aerospace and Defense
Disaggregation of Revenue [Line Items]
Revenues	$ 9,034		$ 18,238

Revenue - Narrative (Details)

Revenue - Narrative (Details) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019USD ($)	Jun. 30, 2019USD ($)
Revenue from Contract with Customer [Abstract]
Contract assets	$ 0.1	$ 0.1
Contract liabilities	0.6	0.6
Revenue recognized, previously included in customer advances and deferred revenue	$ 0.1	$ 0.7