ViewRay (VRAYQ) 10-Q 3 May 19 2019 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2019	Apr. 26, 2019
Document And Entity Information [Abstract]
Entity Registrant Name	ViewRay, Inc.
Entity Central Index Key	0001597313
Document Type	10-Q
Trading Symbol	VRAY
Document Period End Date	Mar. 31, 2019
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Common Stock, Shares Outstanding		96,952,728
Document Fiscal Period Focus	Q1
Document Fiscal Year Focus	2019

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 145,797	$ 167,432
Accounts receivable	27,432	36,867
Inventory	65,140	49,462
Deposits on purchased inventory	7,642	8,142
Deferred cost of revenue	4,342	9,736
Prepaid expenses and other current assets	9,060	6,045
Total current assets	259,413	277,684
Property and equipment, net	15,279	13,958
Restricted cash	1,382	1,933
Right-of-use assets	12,055	0
Other assets	1,496	1,395
TOTAL ASSETS	289,625	294,970
Current liabilities:
Accounts payable	17,891	10,207
Accrued liabilities	16,207	9,983
Customer deposits	14,905	19,968
Operating lease liability, current	1,284	0
Deferred revenue, current	10,287	13,731
Total current liabilities	60,574	53,889
Deferred revenue, net of current portion	5,507	5,744
Long-term debt	55,402	55,364
Warrant liabilities	14,872	11,844
Operating lease liability, noncurrent	11,491	0
Other long-term liabilities	303	820
TOTAL LIABILITIES	148,149	127,661
Commitments and contingencies (Note 6)	0	0
Stockholders’ equity:
Convertible preferred stock, par value of $0.01 per share; 10,000,000 shares authorized at March 31, 2019 and December 31, 2018; no shares issued and outstanding at March 31, 2019 and December 31, 2018	0	0
Common stock, par value of $0.01 per share; 300,000,000 shares authorized at March 31, 2019 and December 31, 2018; 96,933,098 and 96,332,023 shares issued and outstanding at March 31, 2019 and December 31, 2018	959	952
Additional paid-in capital	572,855	565,334
Accumulated deficit	(432,338)	(398,977)
TOTAL STOCKHOLDERS’ EQUITY	141,476	167,309
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 289,625	$ 294,970

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) (Unaudited) - $ / shares	Mar. 31, 2019	Dec. 31, 2018
Statement Of Financial Position [Abstract]
Preferred stock, par value per share	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value per share	$ 0.01	$ 0.01
Common stock, shares authorized	300,000,000	300,000,000
Common stock, shares issued	96,933,098	96,332,023
Common stock, shares outstanding	96,933,098	96,332,023

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenue:
Total revenue	$ 20,284	$ 26,190
Cost of revenue:
Total cost of revenue	25,648	20,620
Gross margin	(5,364)	5,570
Operating expenses:
Research and development	5,031	3,770
Selling and marketing	4,885	3,246
General and administrative	15,109	9,846
Total operating expenses	25,025	16,862
Loss from operations	(30,389)	(11,292)
Interest income	220	2
Interest expense	(759)	(1,866)
Other (expense) income, net	(2,433)	8,342
Loss before provision for income taxes	(33,361)	(4,814)
Provision for income taxes	0	0
Net loss and comprehensive loss	(33,361)	(4,814)
Amortization of beneficial conversion feature related to Series A convertible preferred stock	0	(2,728)
Net loss attributable to common stockholders, basic and diluted	$ (33,361)	$ (7,542)
Net loss per share, basic and diluted	$ (0.34)	$ (0.11)
Weighted-average common shares used to compute net loss per share attributable to common stockholders, basic and diluted	96,741,309	68,943,918
Product
Revenue:
Total revenue	$ 18,874	$ 25,379
Cost of revenue:
Total cost of revenue	22,033	19,711
Service
Revenue:
Total revenue	1,291	692
Cost of revenue:
Total cost of revenue	3,615	909
Distribution Rights
Revenue:
Total revenue	$ 119	$ 119

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Direct Registered Offering	Convertible Preferred Stock	Convertible Preferred StockDirect Registered Offering	Additional Paid-in Capital	Additional Paid-in CapitalDirect Registered Offering	Additional Paid-in CapitalConvertible Preferred Stock	Additional Paid-in CapitalConvertible Preferred StockDirect Registered Offering	Common Stock	Common StockDirect Registered Offering	Accumulated Deficit	Accumulated DeficitDirect Registered Offering
Balance at Dec. 31, 2017	$ 1,987				$ 321,174				$ 666		$ (319,853)
Balance, shares at Dec. 31, 2017									67,653,974
Issuance of common stock from option exercises	378				375				$ 3
Issuance of common stock from option exercises, shares									265,647
Issuance of common stock from releases of restricted stock units, shares									12,468
Stock-based compensation	1,190				1,190
Issuance of common stock, value		$ 30,093				$ 30,052				$ 41
Issuance of common stock, shares										4,090,000
Issuance of preferred Series A stock upon direct registered offering, value		22,207		$ 30		2,728		$ 22,177				$ (2,728)
Issuance of preferred Series A stock upon direct registered offering, share				3,000,581
Issuance of common stock warrants in connection with direct registered offering		$ 6,623				$ 6,623
Net loss	(4,814)										(4,814)
Balance at Mar. 31, 2018	57,664				362,142		$ 22,177		$ 710		(327,395)
Temporary equity balance , shares at Mar. 31, 2018			3,000,581
Temporary equity balance at Mar. 31, 2018			$ 30
Balance, shares at Mar. 31, 2018									72,022,089
Balance at Dec. 31, 2018	167,309				565,334				$ 952		(398,977)
Balance, shares at Dec. 31, 2018									96,332,023
Issuance of common stock from option exercises	$ 2,884				2,877				$ 7
Issuance of common stock from option exercises, shares	588,120								588,120
Stock-based compensation	$ 4,552				4,552
Issuance of common stock from warrant exercises, shares									12,955
Reclassification of warrant liability to additional paid-in capital upon warrant exercises	92				92
Net loss	(33,361)										(33,361)
Balance at Mar. 31, 2019	$ 141,476				$ 572,855				$ 959		$ (432,338)
Balance, shares at Mar. 31, 2019									96,933,098

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Unaudited) (Parenthetical) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)
Direct Registered Offering
Offering cost	$ 177

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (33,361)	$ (4,814)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	946	658
Stock-based compensation	4,552	1,190
Accretion on asset retirement obligation	7	10
Change in fair value of warrant liabilities	3,120	(8,182)
Amortization of debt discount and interest accrual	141	870
Product upgrade reserve	5,601	0
Changes in operating assets and liabilities:
Accounts receivable	9,435	(5,845)
Inventory	(15,795)	(12,021)
Deposits on purchased inventory	500	(2,958)
Deferred cost of revenue	4,628	9,126
Prepaid expenses and other assets	(3,009)	282
Accounts payable	7,048	2,081
Accrued expenses and other long-term liabilities	1,278	725
Customer deposits and deferred revenue	(8,744)	(18,576)
Net cash used in operating activities	(23,653)	(37,454)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(1,249)	(497)
Net cash used in investing activities	(1,249)	(497)
CASH FLOWS FROM FINANCING ACTIVITIES:
Payment of debt issuance cost	(168)	0
Proceeds from the exercise of stock options	2,884	378
Net cash provided by financing activities	2,716	59,478
NET (DECREASE) INCREASE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH	(22,186)	21,527
CASH, CASH EQUIVALENTS AND RESTRICTED CASH — BEGINNING OF PERIOD	169,365	58,532
CASH, CASH EQUIVALENTS AND RESTRICTED CASH — END OF PERIOD	147,179	80,059
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Cash paid for interest	750	996
Cash paid for taxes	7	0
SUPPLEMENTAL NON-CASH INVESTING AND FINANCING ACTIVITIES:
Fair value of common stock warrants reclassified from liability to additional paid-in capital upon exercise	92	0
Right-of-use assets obtained in exchange for new operating lease liabilities	492	0
Transfer of property and equipment from inventory	246	1,415
Purchase of property and equipment in accounts payable and accrued liabilities	615	228
Offering costs included in accounts payable and accrued expenses	0	177
Direct Registered Offering
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from direct registered offering, gross	$ 0	$ 59,100

Background and Organization

Background and Organization	3 Months Ended
	Mar. 31, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Background and Organization	1. Background and Organization ViewRay, Inc., or ViewRay or the Company, and its wholly-owned subsidiary ViewRay Technologies, Inc., designs, manufactures and markets MRIdian, an MR Image-Guided radiation therapy system to simultaneously image and treat cancer patients. Since inception, ViewRay Technologies, Inc. has devoted substantially all of its efforts towards research and development, initial selling and marketing activities, raising capital and the manufacturing, shipment and installation of MRIdian systems. In May 2012, ViewRay Technologies, Inc. was granted clearance from the U.S. Food and Drug Administration, or FDA, to sell MRIdian with Cobalt-60. In November 2013, ViewRay Technologies, Inc. received its first clinical acceptance of a MRIdian with Cobalt-60 at a customer site, and the first patient was treated with that system in January 2014. ViewRay Technologies, Inc. has had the right to affix the CE mark to MRIdian with Cobalt-60 in the European Economic Area since November 2014. In September 2016, the Company received the rights to affix the CE mark to MRIdian Linac, and in February 2017, the Company received 510(k) clearance from the FDA to market MRIdian Linac. The Company’s condensed consolidated financial statements have been prepared on the basis of the Company continuing as a going concern. The Company’s principal sources of liquidity are cash flows from public and private offerings and available borrowings under its term loan agreement, as well as cash receipts from its sales of MRIdian systems. These have historically been sufficient to meet working capital needs, capital expenditures, and debt service obligations. During the three months ended March 31, 2019, the Company incurred a net loss of $33.4 million and used cash in operating activities of $23.7 million. The Company believes that its existing cash balance of $145.8 million as of March 31, 2019, together with anticipated cash proceeds from sales of MRIdian systems will be sufficient to provide liquidity to fund its operations for at least the next 12 months.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation The condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States, or U.S. GAAP, and pursuant to the rules and regulations of the Securities and Exchange Commission, or the SEC. The condensed consolidated financial statements include the accounts of ViewRay, Inc. and its wholly-owned subsidiary, ViewRay Technologies, Inc. All inter-company accounts and transactions have been eliminated in consolidation. In the opinion of management, all adjustments, including normal recurring adjustments, considered necessary for a fair presentation of the Company’s unaudited condensed consolidated financial statements, have been included. The results of operations for the three months ended March 31, 2019 are not necessarily indicative of the results that may be expected for the year ending December 31, 2019 or any future period. These unaudited condensed consolidated financial statements and their notes should be read in conjunction with the audited consolidated financial statements and related notes included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2018. Effective January 1, 2019, the Company adopted the Financial Accounting Standards Board, or FASB, Leases, Significant Accounting Policies The significant accounting policies used in preparation of these condensed consolidated financial statements are disclosed in the notes to consolidated financial statements included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2018 filed with the SEC on March 15, 2019, and have not changed significantly since that filing, except for the January 1, 2019 adoption of the new accounting guidance Topic 842, Leases Recent Accounting Pronouncements In August 2018, the FASB issued Accounting Standards Update, or ASU, No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework- Changes to the Disclosure Requirements for Fair Value Measurement, Recently Adopted Accounting Pronouncements In February 2016, the FASB issued ASU, No. 2016-02, Leases and issued subsequent amendments to the initial guidance in September 2017 within ASU 2017-13, in January 2018 within ASU 2018-01, in July 2018 within ASU 2018-10 and ASU 2018-11, and in March 2019 within ASU 2019-01 (collectively, Topic 842). Topic 842 supersedes Topic 840, Leases, and requires lessees to recognize on their balance sheets all leases, with the exception of short-term leases, as a right-of-use asset and a corresponding lease liability measured at the present value of the lease payments. Leases will be classified as finance or operating, with classification affecting the pattern and classification of expense recognition in the income statement. The new standard requires expanded disclosures regarding leasing arrangements. Effective January 1, 2019, the Company adopted Topic 842 using a modified retrospective transition approach by applying the new standard to all leases existing at the date of initial application and not restating comparative periods. There was no cumulative-effect adjustment recorded to retained deficit upon adoption. Topic 842 provides several optional practical expedients in transition. The Company elected to use the package of practical expedients permitted under the transition guidance, which allows the Company not to reassess its prior conclusions about lease identification, lease classification and initial direct costs for any leases that existed prior to January 1, 2019. The Company did not elect to use the other practical expedients provided. Upon adoption, the Company recognized the right-of-use assets and operating lease liabilities totaling approximately $11.9 million and $12.6 million, respectively, to reflect the present value of remaining lease payments under existing lease arrangements with no impact to the opening balance of retained deficit as a result of adoption. The difference between the leased assets and lease liabilities represents the existing deferred rent liabilities balance, resulting from historical straight-lining of operating leases, which was effectively reclassified upon adoption to reduce the measurement of the leased assets. In determining the present value of lease payments, the Company uses the rate implicit in the lease or when such rate is not readily available, we utilize our incremental borrowing rate based on the information available at the lease commencement date. Lease expense is recognized on a straight-line basis over the expected lease term. In determining the expected lease term, the Company may include options to extend or terminate the lease when it is reasonably certain that it will exercise any such option. For more information on the impact of adoption and the disclosures required by the new standard, refer to Note 6, Commitments and Contingencies. In June 2018, the FASB issued ASU No. 2018-07, Compensation — Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting

Balance Sheet Components

Balance Sheet Components	3 Months Ended
	Mar. 31, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Balance Sheet Components	3. Balance Sheet Components Property and Equipment, Net Property and equipment consisted of the following (in thousands): March 31, 2019 December 31, 2018 Prototype $ 12,247 $ 12,425 Machinery and equipment 13,871 12,654 Leasehold improvements 4,621 4,600 Furniture and fixtures 665 636 Software 1,296 1,250 Construction in progress 1,216 148 Property and equipment, gross 33,916 31,713 Less: accumulated depreciation and amortization (18,637 ) (17,755 ) Property and equipment, net $ 15,279 $ 13,958 Depreciation and amortization expense related to property and equipment were $0.9 million and $0.7 million during the three months ended March 31, 2019 and 2018, respectively. Accrued Liabilities Accrued liabilities consisted of the following (in thousands): March 31, 2019 December 31, 2018 Accrued payroll and related benefits $ 5,828 $ 5,047 Accrued accounts payable 3,736 3,626 Payroll withholding tax, sales and other tax payable 439 782 Accrued legal, accounting and professional fees 721 360 Product upgrade reserve 4,964 — Other 519 168 Total accrued liabilities $ 16,207 $ 9,983 Deferred Revenue Deferred revenue consisted of the following (in thousands): March 31, 2019 December 31, 2018 Deferred revenue: Product $ 5,424 $ 9,623 Service 7,618 6,981 Distribution rights 2,752 2,871 Total deferred revenue 15,794 19,475 Less: current portion of deferred revenue (10,287 ) (13,731 ) Noncurrent portion of deferred revenue $ 5,507 $ 5,744 Other Long-Term Liabilities March 31, 2019 December 31, 2018 Accrued interest, noncurrent portion $ 104 $ — Deferred rent, noncurrent portion — 628 Other 199 192 Total other-long term liabilities $ 303 $ 820

Fair Value of Financial Instrum

Fair Value of Financial Instruments	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	4. Fair Value of Financial Instruments Assets and liabilities recorded at fair value on a recurring basis in the balance sheets are categorized based upon the level of judgment associated with the inputs used to measure their fair values. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The standard describes a fair value hierarchy based on three levels of inputs, of which the first two are considered observable and the last unobservable, as follows: Level 1—Quoted prices in active markets for identical assets or liabilities. Level 2—Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices 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 assets’ or liabilities’ fair value measurement level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The Company’s financial instruments that are carried at fair value mainly consist of Level 1 assets and Level 3 liabilities. Level 1 assets include highly liquid bank deposits and money market funds, which were not material at March 31, 2019 and December 31, 2018. Level 3 liabilities that are measured on a recurring basis relate to the 2017 and 2016 Placement Warrants, as described in Note 9. Placement warrant liabilities are valued using the Black-Scholes option-pricing model. Generally, increases (decreases) in the fair value of the underlying stock, volatility and estimated term would result in a directionally similar impact to the fair value of the warrants (see Note 9). The gains and losses from re-measurement of Level 3 financial liabilities are recorded as part of other (expense) income, net in the condensed consolidated statements of operations and comprehensive loss. During the three months ended March 31, 2019 and 2018, the Company recorded a loss of $3.0 million and a gain of $8.2 million, respectively, related to the change in fair value of the 2017 and 2016 Placement Warrants. There were no transfers between Level 1, Level 2 and Level 3 in any periods presented. The following table sets forth the fair value of the Company’s financial liabilities by level within the fair value hierarchy (in thousands): At March 31, 2019 Level 1 Level 2 Level 3 Total 2017 Placement Warrants Liability $ — $ — $ 8,955 $ 8,955 2016 Placement Warrants Liability — — 5,917 5,917 Total $ — $ — $ 14,872 $ 14,872 At December 31, 2018 Level 1 Level 2 Level 3 Total 2017 Placement Warrants Liability $ — $ — $ 7,115 $ 7,115 2016 Placement Warrants Liability — — 4,729 4,729 Total $ — $ — $ 11,844 $ 11,844 The following table sets forth a summary of the changes in fair value of the Company’s Level 3 financial liabilities (in thousands): Three Months Ended March 31, 2019 2018 Fair value, beginning of period $ 11,844 $ 22,420 Change in fair value of Level 3 financial liabilities 3,120 (8,182 ) Fair value of 2016 Placement Warrants at exercise (66 ) — Fair value of 2017 Placement Warrants at exercise (26 ) — Fair value, end of period $ 14,872 $ 14,238

Debt

Debt	3 Months Ended
	Mar. 31, 2019
Debt Instruments [Abstract]
Debt	5. Debt SVB Term Loan In December 2018, the Company entered into a term loan agreement, or the SVB Term Loan, with Silicon Valley Bank, for a principal amount of $56.0 million. The SVB Term Loan has a maturity date of December 1, 2023 and bears interest at a rate of 6.30% per annum to be paid monthly over the term of the loan. Beginning on December 1, 2020 (or June 1, 2021, if the Company achieves a trailing twelve-month revenue of at least a specified amount and elects to apply such later date), the Company will make thirty-six equal monthly payments of principal (or thirty equal payments, if the Company so elects). In addition, upon repayment of the SVB Term Loan in full, the Company will make a final payment equal to 3.15% of the original aggregate principal amount of the SVB Term Loan. The Company used the proceeds of the SVB Term Loan and cash on hand to repay in full its outstanding obligations under its then outstanding term loan, or the CRG Term Loan and to pay fees and expenses related thereto. The Company accounted for the termination of the CRG Term Loan as a debt extinguishment and recorded a debt extinguishment loss of $2.4 million from the difference between the net carrying amount of debt and the amount paid. The debt extinguishment loss includes $0.3 million in write-off of unamortized debt discount and debt issuance costs associated with the CRG Term Loan. The Company received net proceeds from the SVB Term Loan of $55.4 million after related legal and consulting fees totaling $0.6 million. Such fees are accounted for as debt discount and issuance costs and presented as a direct deduction from the carrying amount of debt on the Company’s consolidated balance sheets. Debt discount, issuance costs and the final payment are amortized or accreted as interest expense over the term of the loan using the effective interest method. The SVB Term Loan is secured by substantially all assets of the Company, except that the collateral does not include any intellectual property held by the Company, provided, however, the collateral shall include all accounts and proceeds of such intellectual property. The SVB Term Loan contains customary representations and warranties and customary affirmative and negative covenants applicable to the Company and its subsidiaries, including, among other things, restrictions on indebtedness, liens, investments, mergers, dispositions, prepayment of other indebtedness, dividends and other distributions and transactions with affiliates. The SVB Term Loan also contains financial covenants that require the Company to maintain a minimum cash balance in accounts maintained at Silicon Valley Bank or one of its affiliates or else comply with a liquidity ratio and/or a minimum revenue target. The SVB Term Loan includes standard events of default, including, among other things, subject in certain cases to customary grace periods, thresholds and notice requirements, the Company’s failure to fulfill its obligations under the SVB Term Loan or the occurrence of a material adverse change in the Company's business, operations, or condition (financial or otherwise). In the event of default by the Company under the SVB Term Loan, Silicon Valley Bank would be entitled to exercise its remedies thereunder, including the right to accelerate the debt, upon which the Company may be required to repay all amounts then outstanding under the SVB Loan, which could harm the Company's financial condition. The Company’s scheduled future payments on the SVB Term Loan at March 31, 2019 are as follows (in thousands): Year Ended December 31, The remainder of 2019 $ - 2020 1,555 2021 18,667 2022 18,667 2023 17,111 Total future principal payments 56,000 Less: unamortized debt discount (598 ) Carrying value of long-term debt 55,402 Less: current portion — Long-term portion $ 55,402

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	6. Commitments and Contingencies Operating Leases The Company leases office space in Oakwood Village, Ohio and Mountain View, California under noncancelable operating lease agreements. The Company leases and occupies approximately 19,800 square feet of office space in Oakwood Village, Ohio, which expires in October 2019. In April 2019, the Company entered into an amendment to extend the term of the lease agreement through October 2021. In June 2014, the Company entered into an office lease agreement to lease approximately 25,500 square feet of office space located in Mountain View, California, which expires in November 2019. In June 2018, the Company entered into an amendment to extend the term of the lease agreement through July 2025. In April 2018, the Company entered into a lease agreement to lease approximately 24,600 square feet of additional office space located in Mountain View, California. The lease commenced in December 2018 and will expire in December 2025. The Company has the option to extend the term of the lease for a period of up to five years. In recognition of the right-of-use assets and the related lease liabilities, with the exception of the Oakwood Village, Ohio lease, the options to extend the lease term have not been included as the Company is not reasonably certain that it will exercise any such option. At March 31, 2019, the weighted-average remaining lease term in years is 6.4 years and the weighted-average discount rate used is 7.7%. During the three months ended March 31, 2019, the Company recognized the following lease costs and cash flow transactions arising from lease transactions: Three Months Ended March 31, 2019 Operating lease cost $ 626 Cash paid for amounts included in the measurement of lease liabilities 514 Right-of-use assets obtained in exchange for new operating lease liabilities 492 At March 31, 2019, the future payments and interest expense for the operating leases are as follows: Year Ending December 31, Future Payments The remainder of 2019 $ 1,584 2020 2,522 2021 2,567 2022 2,496 2023 2,571 2024 2,604 Thereafter 1,924 Total undiscounted cash flows $ 16,268 Less: imputed interest (3,493 ) Present value of lease liabilities $ 12,775 The rent expense for operating leases for the three months ended March 31, 2018 using the accounting guidance in effect at that time was $0.2 million. At December 31, 2018, the future minimum payments for the operating leases were as follows (in thousands): Year Ending December 31, Future Payments 2019 $ 2,070 2020 2,353 2021 2,424 2022 2,496 2023 2,571 Thereafter 4,532 Total future minimum payments $ 16,446 Legal Proceedings In the normal course of business, the Company may become involved in legal proceedings. The Company will accrue a liability for legal proceedings when it is probable that a liability has been incurred and the amount can be reasonably estimated. Significant judgment is required to determine both probability and the estimated amount. When only a range of possible loss can be established, the most probable amount in the range is accrued. If no amount within this range is a better estimate than any other amount within the range, the minimum amount in the range is accrued. At March 31, 2019 and December 31, 2018, the Company was not involved in any material legal proceedings. Purchase Commitments At March 31, 2019 the Company had $7.3 million in outstanding firm purchase commitments.

Revenue

Revenue	3 Months Ended
	Mar. 31, 2019
Revenue From Contract With Customer [Abstract]
Revenue	7. Revenue The Company derives revenue primarily from the sale of MRIdian systems and related services as well as support and maintenance services on sold systems. Revenue is categorized as product revenue, service revenue and distribution rights revenue. The following table presents revenue disaggregated by type and geography (in thousands): Three Months Ended March 31, 2019 2018 U.S. Product $ — $ 13,535 Service 634 396 Total U.S. revenue $ 634 $ 13,931 Outside of U.S. ("OUS") Product $ 18,874 $ 11,844 Service 657 296 Distribution rights 119 119 Total OUS revenue $ 19,650 $ 12,259 Total Product $ 18,874 $ 25,379 Service 1,291 692 Distribution rights 119 119 Total revenue $ 20,284 $ 26,190 Distribution agreement In connection with the distribution agreement entered into in December 2014, between the Company and Itochu Corporation, or Itochu, the Company received a distribution fee of $4.0 million in three installments from Itochu for serving as the Company’s exclusive distributor for the sale and delivery of its MRIdian systems within Japan. In August 2016, the Company started recognizing distribution rights revenue ratably over the remaining term of the exclusive distribution agreement of approximately 8.5 years. A time-elapsed method is used to measure progress because control is transferred evenly over the remaining contractual period. Contract Balances The timing of revenue recognition, billings and cash collections results in short-term and long-term trade receivables, customer deposits, deferred revenues and deferred cost of revenue on the condensed consolidated balance sheets. Trade receivables are recorded at the original invoiced amount, net of an estimated allowance for doubtful accounts. Trade credit is generally extended on a short-term basis. The Company occasionally provides for long-term trade credit for its maintenance services so that the period between when the services are rendered to its customers and when the customers pay for that service is within one year. Thus, the Company’s trade receivables do not bear interest or contain a significant financing component. Long-term trade receivables of $0.4 million were reported within other assets in the condensed consolidated balance sheets at March 31, 2019 and at December 31, 2018. These amounts are billed in accordance with the terms of the customer contracts to which they relate and are expected to be collected three to four years from the date of invoice as the underlying maintenance services are rendered. At times, billing occurs subsequent to revenue recognition, resulting in an unbilled receivable which represents a contract asset. This contract asset is recorded as an unbilled receivable and reported as part of accounts receivable on the condensed consolidated balance sheets. Trade receivables are periodically evaluated for collectability based on past credit history of the respective customers and their current financial condition. Changes in the estimated collectability of trade receivables are included in the results of operations for the period in which the estimate is revised. Trade receivables that are deemed uncollectible are offset against the allowance for doubtful accounts. The Company generally does not require collateral for trade receivables. There was no allowance for doubtful accounts recorded at March 31, 2019 or December 31, 2018. Customer deposits represent payments received in advance of system installation. For domestic and international sales, advance payments received prior to inventory shipments and customer acceptance are recorded as customer deposits. Advance payments are subsequently reclassified to deferred revenue upon inventory shipment when the title and risk of loss of inventory items transfer to customers. All customer deposits, including those that are expected to be a deposit for more than one year, are classified as current liabilities based on consideration of the Company’s normal operating cycle (the time between acquisition of the inventory components and the final cash collection from customers on these inventory components) which is in excess of one year. Deferred revenue consists of deferred product revenue and deferred service revenue. Deferred product revenue arises from timing differences between the fulfillment of contract obligations and satisfaction of all revenue recognition criteria consistent with the Company’s revenue recognition policy. Deferred service revenue results from the advance billing for services to be delivered over a period of time. Deferred revenues expected to be realized within one year or normal operating cycle are classified as current liabilities. Deferred cost of revenue consists of cost for inventory items that have been shipped with title and risk of loss transferred to the customer, but the customer acceptance has not yet been received. Deferred cost of revenue is included as part of current assets as the corresponding deferred product revenue is expected to be realized within one year or the Company’s normal operating cycle. During the three months ended March 31, 2019, the Company recognized $7.9 million of revenue that was included in the deferred revenue balance at the beginning of the reporting period. During the three months ended March 31, 2018, the Company recognized $22.2 million of revenue that was included in the deferred revenue balance at the beginning of the 2018 reporting period. Variable Consideration The Company records revenue from customers in an amount that reflects the transaction price it expects to be entitled to after transferring control of those goods or services. The Company estimates the transaction price at contract inception, including any variable consideration, and updates the estimate each reporting period for any changes. For the three months ended March 31, 2019, the Company recognized $0.9 million in revenue from performance obligations satisfied in the prior period. The cumulative catch-up adjustment resulted from a change in transaction price related to variable consideration that was constrained in prior periods.

Equity Financing

Equity Financing	3 Months Ended
	Mar. 31, 2019
Equity [Abstract]
Equity Financing	8. Equity Financing Public Offering of Common Stock On August 14, 2018, the Company entered into an underwriting agreement with Morgan Stanley & Co. LLC and Jefferies LLC, as representatives of several underwriters, or the “Underwriters”, in connection with the issuance and sale of 16,216,217 shares of the Company’s common stock at a public offering price of $9.25 per share. In addition, the Company granted the Underwriters a 30-day option to purchase up to 2,432,432 additional shares of common stock on the same terms, which the Underwriters exercised in full. The Company completed the offering on August 17, 2018 under which it received aggregate net proceeds of approximately $161.9 million, after deducting underwriting discounts and commissions and offering expenses payable by the Company. Direct Registered Offerings In February 2018, the Company entered into a securities purchase agreement pursuant to which it sold (i) 4,090,000 shares of its common stock; (ii) 3,000,581 shares of its Series A convertible preferred stock and (iii) warrants to purchase 1,418,116 shares of its common stock, or the 2018 Offering Warrants, for total gross proceeds of $59.1 million, or the March 2018 Direct Registered Offering. The March 2018 Direct Registered Offering was closed on March 5, 2018. The 2018 Offering Warrants have an exercise price of $8.31 per share, became exercisable upon issuance and expire in March 2025. Private Placements In September 2016, the Company completed the final closing of a private placement offering, or the 2016 Private Placement, through which it sold (i) 4,602,506 shares of its common stock and (ii) warrants that provide the warrant holders the right to purchase 1,380,745 shares of common stock, or the 2016 Placement Warrants, and raised total gross proceeds of $13.8 million. The 2016 Placement Warrants have an exercise price of $2.95 per share, are exercisable at any time at the option of the holder and expire seven years from the date of issuance. In January 2017, the Company completed the final closing of a private placement offering, or the 2017 Private Placement, through which it sold (i) 8,602,589 shares of its common stock and (ii) warrants that provide the warrant holders the right to purchase 1,720,512 shares of its common stock, or the 2017 Placement Warrants, and raised total gross proceeds of $26.1 million. The 2017 Placement Warrants have an exercise price of $3.17 per share, became exercisable in July 2017 and expire in January 2024. At-The-Market Offering of Common Stock In January 2017, the Company filed a shelf registration statement on Form S-3 with the SEC, which included a base prospectus covering the offering, issuance and sale of up to a maximum aggregate offering of $75.0 million of the Company’s common stock, preferred stock, debt securities, warrants, purchase contracts and/or units. In January and April 2017, the Company agreed to sell up to a cumulative $50.0 million of its common stock in accordance with the terms of a sales agreement with , pursuant to an at-the-market offering program in accordance with Rule 415(a)(4) under the Securities Act. In January 2019, the Company filed a registration statement with the SEC which covers the offering, issuance and sale of up to a maximum aggregate offering price of $250.0 million of our common stock, preferred stock, debt securities, warrants, purchase contracts and/or units, including up to $100.0 million of the Company’s common shares pursuant to the Company’s at-the-market offering program with FBR. As of March 31, 2019, the Company has sold approximately $40.4 million under this at-the-market offering program. No securities were sold in the three months ended March 31, 2019.

Warrants

Warrants	3 Months Ended
	Mar. 31, 2019
Equity [Abstract]
Warrants	9 . Warrants Equity Classified Common Stock Warrants In connection with a debt financing in December 2013, the Company issued warrants to purchase 128,231 shares of its common stock with an exercise price of $5.84 per share. These warrants are exercisable any time at the option of the holder until December 16, 2023. None of these warrants have been exercised to date and they all remained outstanding at March 31, 2019. In connection with the merger of the Company and ViewRay Technologies, Inc. in July 2015, or the Merger, in July and August 2015, the Company conducted a private placement offering during which the Company the five-year anniversary of its date of issuance In connection with the March 2018 Direct Registered Offering, the Company issued warrants to purchase 1,418,116 shares of common stock at an exercise price of $8.31 per share, or the 2018 Offering Warrants. The 2018 Offering Warrants became exercisable upon issuance and expire in March 2025. None of the 2018 Offering Warrants have been exercised to date and they all remained outstanding at March 31, 2019. As separate classes of securities were issued in a bundled transaction, the gross proceeds from the March 2018 Direct Registered Offering of $59.1 million was allocated to common stock, Series A convertible preferred stock and the 2018 Offering Warrants based on their respective relative fair value upon issuance. The aggregate fair value of the 2018 Offering Warrants of $7.4 million was estimated using the Black-Scholes option-pricing model with the following weighted-average assumptions: expected term of seven years, expected volatility of 62.5%, risk-free interest rate of 2.8% and expected dividend yield of 0%. The allocated proceeds from the 2018 Offering Warrants of $6.6 million was recorded in additional paid-in-capital. Liability Classified Common Stock Warrants In connection with private placement offerings in 2017 and 2016, the Company issued common stock warrants, or the 2017 and 2016 Placement Warrants, which contain protection whereby the warrant holders will have the right to receive cash in the amount equal to the Black-Scholes value of the warrants upon the occurrence of a Change of Control, as defined in the 2017 and 2016 Placement Warrants. The 2017 and 2016 Placement Warrants were accounted for as a liability at the date of issuance and are adjusted to fair value at each balance sheet date, with the change in fair value recorded as a component of other income (expense), net in the condensed consolidated statements of operations and comprehensive loss. The key terms of the 2017 and 2016 Placement Warrants are as follows: Issuance Date Term Exercise Price Per Share Warrants Exercised during the Three Months Ended March 31, 2019 Warrants Outstanding at March 31, 2019 2017 Placement Warrants January 2017 7 years $ 3.17 6,022 1,703,510 2016 Placement Warrants August and September 2016 7 years $ 2.95 15,549 1,115,066 Total 21,571 2,818,576 During the three months ended March 31, 2019 and 2018, the Company recorded a loss of $3.0 million and a gain of $8.2 million, respectively, related to the change in fair value of the 2016 and 2017 Placement Warrants. The fair value of the 2016 and 2017 Placement Warrants at March 31, 2019 and December 31, 2018, respectively, was estimated using the Black-Scholes option-pricing model and the following weighted-average assumptions: 2017 Placement Warrants 2016 Placement Warrants March 31, 2019 December 31, 2018 March 31, 2019 December 31, 2018 Expected term (in years) 4.8 5.1 4.4 4.7 Expected volatility 59.4% 60.8% 60.0% 60.9% Risk-free interest rate 2.2% 2.5% 2.2% 2.5% Expected dividend yield 0% 0% 0 0%

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	1 0 . Stock-Based Compensation A summary of the Company’s stock option activity and related information is as follows: Options Outstanding Shares Available for Grant Number of Stock Options Outstanding Weighted- Average Exercise Price Weighted- Average Remaining Contractual Life (Years) Aggregate Intrinsic Value (In thousands) Balance at December 31, 2018 1,908,626 11,603,708 $ 6.64 7.6 $ 10,151 Additional options authorized 3,853,280 Options granted (1,872,022 ) 1,872,022 8.28 Options exercised - (588,120 ) 4.90 Options canceled 79,293 (79,293 ) 7.49 RSUs granted (651,392 ) Balance at March 31, 2019 3,317,785 12,808,317 $ 6.95 7.9 $ 16,290 Vested and exercisable at March 31, 2019 4,071,182 $ 4.32 5.9 $ 12,759 Vested and expected to vest at March 31, 2019 12,181,953 $ 6.89 7.9 $ 16,094 The weighted-average grant date fair value of options granted to employees was $4.78 and $4.75 per share during the three months ended March 31, 2019 and 2018, respectively. The grant date fair value of options vested was $1.2 million and $1.1 million during the three months ended March 31, 2019 and 2018, respectively. Aggregate intrinsic value represents the difference between the estimated fair value of the underlying common stock and the exercise price of outstanding, in-the-money options. The aggregate intrinsic value of options exercised was $1.9 million and $1.6 million during the three months ended March 31, 2019 and 2018, respectively. At March 31, 2019, total unrecognized compensation cost related to stock options granted to employees, net of estimated forfeitures, was $34.1 million which is expected to be recognized over a weighted-average period of 3.2 years. Determination of Fair Value The determination of the fair value of stock options on the date of grant using an option-pricing model is affected by the estimated fair value of the Company’s common stock, as well as assumptions regarding a number of complex and subjective variables. The variables used to calculate the fair value of stock options using the Black-Scholes option-pricing model include actual and projected employee stock option exercise behaviors, expected price volatility of the Company’s common stock, the risk-free interest rate and expected dividends. Each of these inputs is subjective and generally requires significant judgment to determine. The fair value of employee stock option is estimated at the date of grant using a Black-Scholes option-pricing model with the following weighted-average assumptions: Three Months Ended March 31, 2019 2018 Expected term (in years) 6.0 5.9 Expected volatility% 60.4% 61.7% Risk-free interest rate% 2.6% 2.6% Expected dividend yield% 0.0% 0.0% Restricted Stock Units From time to time, the Company grants Restricted Stock Units, or RSUs, to its board of directors for their services. These RSUs are either fully vested upon issuance or vest over a period of time from the grant date and will be released and settled upon termination of the board member’s services or the occurrence of a change in control event. In January 2019, the Company granted RSUs to its Board of Directors as part of the director compensation program. In March 2019, the Company granted RSUs to several employees. The fair value of RSUs is based on the closing market price of the Company’s common stock on the grant date. RSUs Number of Shares Weighted Average Grant Date Fair Value Unvested at December 31, 2018 1,736,234 $ 9.65 RSUs granted 651,392 7.69 RSUs vested (21,149 ) 6.33 Unvested at March 31, 2019 2,366,477 $ 9.14 Vested and unreleased 142,656 Outstanding at March 31, 2019 2,509,133 The total grant date fair value of RSUs awarded was $5.0 million for the three months ended March 31, 2019. The total fair value of RSUs vested was $0.1 million for the three months ended March 31, 2019. There were no RSUs awarded or vested in the three months ended March 31, 2018. As of March 31, 2019, total unrecognized stock-based compensation cost related to RSUs was $16.2 million, which is expected to be recognized over a weighted-average period of 2.3 years. As of March 31, 2019, 2,191,333 shares of RSUs are expected to vest. Stock-Based Compensation Expense Total stock-based compensation expense recognized in the Company’s condensed consolidated statements of operations and comprehensive loss is classified as follows (in thousands): Three Months Ended March 31, 2019 2019 2018 Research and development $ 391 $ 203 Selling and marketing 265 127 General and administrative 3,896 860 Total stock-based compensation expense $ 4,552 $ 1,190 During the three months ended March 31, 2019 and 2018, there was no stock-based compensation expense capitalized as a component of inventory or recognized in cost of revenue. Stock-based compensation relating to stock-based awards granted to consultants was insignificant during the three months ended March 31, 2019 and 2018.

Income Tax

Income Tax	3 Months Ended
	Mar. 31, 2019
Income Tax Disclosure [Abstract]
Income Tax	1 1 . Income Tax Due to the current operating losses, the Company recorded zero income tax expense during the three months ended March 31, 2019 and 2018, respectively. During these periods, the Company’s activities were limited to U.S. federal and state tax jurisdictions, as it does not have any significant foreign operations. The federal and state effective tax rate before valuation allowance is approximately 24% for the three months ended March 31, 2019. Due to the Company’s history of cumulative losses and after considering all the available objective evidence, management concluded that it is not more likely than not that all of the Company’s net deferred tax assets will be realized. Accordingly, the Company’s deferred tax assets, which includes net operating loss, or NOL, carryforwards and tax credits related primarily to research and development continue to be subject to a valuation allowance as of March 31, 2019. The Company expects to continue to maintain a full valuation allowance until there is sufficient evidence to support recoverability of its deferred tax assets. The Company had unrecognized tax benefits of $2.1 million and $1.6 million at March 31, 2019 and December 31, 2018, respectively. The reversal of the uncertain tax benefits would not affect the effective tax rate to the extent that the Company continues to maintain a full valuation allowance against its deferred tax assets. Unrecognized tax benefits may change during the next 12 months for items that arise in the ordinary course of business. Interest and/or penalties related to income tax matters are recognized as a component of income tax expense. At March 31, 2019, and December 31, 2018, there were no accrued interest and penalties related to uncertain tax positions.

Net Loss per Share

Net Loss per Share	3 Months Ended
	Mar. 31, 2019
Earnings Per Share [Abstract]
Net Loss per Share	1 2 . Net Loss per Share Since the Company was in a loss position for all periods presented, diluted net loss per common share is the same as basic net loss per common share for all periods presented, because the inclusion of all potential common shares outstanding would have an anti-dilutive effect. The following weighted-average common stock equivalents were excluded from the calculation of diluted net loss per share for the periods presented, because including them would have an anti-dilutive effect: Three Months Ended March 31, 2019 2018 Series A convertible preferred stock (if converted) — 900,174 Options to purchase common stock 8,399,374 8,600,707 Common stock warrants 4,404,673 3,819,190 Restricted stock units 511,329 137,168 Total 13,315,376 13,457,239

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2019
Related Party Transactions [Abstract]
Related Party Transactions	1 3 . Related Party Transactions In December 2004, the Company entered into a licensing agreement with the University of Florida Research Foundation, or UFRF, whereby UFRF granted the Company a worldwide exclusive license to certain of UFRF’s patents in exchange for 33,652 shares of common stock and a 1% royalty, with a minimum $0.1 million royalty payment per quarter, from sales of products developed and sold by the Company utilizing the licensed patents. Minimum royalty payments in any calendar year are credited against earned royalties for such calendar year. Royalty expenses based on 1% of net sales were $0.2 million and $0.0 million during the three months ended March 31, 2019 and 2018, respectively, and were recorded as product cost of revenue. In January 2017, the Company entered into a sales consulting agreement with Puissance Capital Management, or PCM, to assist with business development activities in a key market in Asia. PCM is the investment manager of Puissance Cross Board Opportunities LLP, a stockholder in the Company. Theodore T. Wang, Ph.D., a member of the Company’s board of directors, is the managing member of the general partners of PCM. The sales consulting agreement has a term of one year with a total consideration of $1.3 million. This amount has been fully expensed in the first quarter of 2018.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States, or U.S. GAAP, and pursuant to the rules and regulations of the Securities and Exchange Commission, or the SEC. The condensed consolidated financial statements include the accounts of ViewRay, Inc. and its wholly-owned subsidiary, ViewRay Technologies, Inc. All inter-company accounts and transactions have been eliminated in consolidation. In the opinion of management, all adjustments, including normal recurring adjustments, considered necessary for a fair presentation of the Company’s unaudited condensed consolidated financial statements, have been included. The results of operations for the three months ended March 31, 2019 are not necessarily indicative of the results that may be expected for the year ending December 31, 2019 or any future period. These unaudited condensed consolidated financial statements and their notes should be read in conjunction with the audited consolidated financial statements and related notes included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2018. Effective January 1, 2019, the Company adopted the Financial Accounting Standards Board, or FASB, Leases,
Significant Accounting Policies	Significant Accounting Policies The significant accounting policies used in preparation of these condensed consolidated financial statements are disclosed in the notes to consolidated financial statements included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2018 filed with the SEC on March 15, 2019, and have not changed significantly since that filing, except for the January 1, 2019 adoption of the new accounting guidance Topic 842, Leases
Recent Accounting Pronouncements	Recent Accounting Pronouncements In August 2018, the FASB issued Accounting Standards Update, or ASU, No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework- Changes to the Disclosure Requirements for Fair Value Measurement,
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements In February 2016, the FASB issued ASU, No. 2016-02, Leases and issued subsequent amendments to the initial guidance in September 2017 within ASU 2017-13, in January 2018 within ASU 2018-01, in July 2018 within ASU 2018-10 and ASU 2018-11, and in March 2019 within ASU 2019-01 (collectively, Topic 842). Topic 842 supersedes Topic 840, Leases, and requires lessees to recognize on their balance sheets all leases, with the exception of short-term leases, as a right-of-use asset and a corresponding lease liability measured at the present value of the lease payments. Leases will be classified as finance or operating, with classification affecting the pattern and classification of expense recognition in the income statement. The new standard requires expanded disclosures regarding leasing arrangements. Effective January 1, 2019, the Company adopted Topic 842 using a modified retrospective transition approach by applying the new standard to all leases existing at the date of initial application and not restating comparative periods. There was no cumulative-effect adjustment recorded to retained deficit upon adoption. Topic 842 provides several optional practical expedients in transition. The Company elected to use the package of practical expedients permitted under the transition guidance, which allows the Company not to reassess its prior conclusions about lease identification, lease classification and initial direct costs for any leases that existed prior to January 1, 2019. The Company did not elect to use the other practical expedients provided. Upon adoption, the Company recognized the right-of-use assets and operating lease liabilities totaling approximately $11.9 million and $12.6 million, respectively, to reflect the present value of remaining lease payments under existing lease arrangements with no impact to the opening balance of retained deficit as a result of adoption. The difference between the leased assets and lease liabilities represents the existing deferred rent liabilities balance, resulting from historical straight-lining of operating leases, which was effectively reclassified upon adoption to reduce the measurement of the leased assets. In determining the present value of lease payments, the Company uses the rate implicit in the lease or when such rate is not readily available, we utilize our incremental borrowing rate based on the information available at the lease commencement date. Lease expense is recognized on a straight-line basis over the expected lease term. In determining the expected lease term, the Company may include options to extend or terminate the lease when it is reasonably certain that it will exercise any such option. For more information on the impact of adoption and the disclosures required by the new standard, refer to Note 6, Commitments and Contingencies. In June 2018, the FASB issued ASU No. 2018-07, Compensation — Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting

Balance Sheet Components (Table

Balance Sheet Components (Tables)	3 Months Ended
	Mar. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Schedule of Property and Equipment, Net	Property and equipment consisted of the following (in thousands): March 31, 2019 December 31, 2018 Prototype $ 12,247 $ 12,425 Machinery and equipment 13,871 12,654 Leasehold improvements 4,621 4,600 Furniture and fixtures 665 636 Software 1,296 1,250 Construction in progress 1,216 148 Property and equipment, gross 33,916 31,713 Less: accumulated depreciation and amortization (18,637 ) (17,755 ) Property and equipment, net $ 15,279 $ 13,958
Schedule of Accrued Liabilities	Accrued liabilities consisted of the following (in thousands): March 31, 2019 December 31, 2018 Accrued payroll and related benefits $ 5,828 $ 5,047 Accrued accounts payable 3,736 3,626 Payroll withholding tax, sales and other tax payable 439 782 Accrued legal, accounting and professional fees 721 360 Product upgrade reserve 4,964 — Other 519 168 Total accrued liabilities $ 16,207 $ 9,983
Schedule of Deferred Revenue	Deferred revenue consisted of the following (in thousands): March 31, 2019 December 31, 2018 Deferred revenue: Product $ 5,424 $ 9,623 Service 7,618 6,981 Distribution rights 2,752 2,871 Total deferred revenue 15,794 19,475 Less: current portion of deferred revenue (10,287 ) (13,731 ) Noncurrent portion of deferred revenue $ 5,507 $ 5,744
Schedule of Other Long Term Liabilities	Other Long-Term Liabilities March 31, 2019 December 31, 2018 Accrued interest, noncurrent portion $ 104 $ — Deferred rent, noncurrent portion — 628 Other 199 192 Total other-long term liabilities $ 303 $ 820

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Schedule of Fair Value of Financial Liabilities	The following table sets forth the fair value of the Company’s financial liabilities by level within the fair value hierarchy (in thousands): At March 31, 2019 Level 1 Level 2 Level 3 Total 2017 Placement Warrants Liability $ — $ — $ 8,955 $ 8,955 2016 Placement Warrants Liability — — 5,917 5,917 Total $ — $ — $ 14,872 $ 14,872 At December 31, 2018 Level 1 Level 2 Level 3 Total 2017 Placement Warrants Liability $ — $ — $ 7,115 $ 7,115 2016 Placement Warrants Liability — — 4,729 4,729 Total $ — $ — $ 11,844 $ 11,844
Summary of Changes in Fair Value of Level 3 Financial Liabilities	The following table sets forth a summary of the changes in fair value of the Company’s Level 3 financial liabilities (in thousands): Three Months Ended March 31, 2019 2018 Fair value, beginning of period $ 11,844 $ 22,420 Change in fair value of Level 3 financial liabilities 3,120 (8,182 ) Fair value of 2016 Placement Warrants at exercise (66 ) — Fair value of 2017 Placement Warrants at exercise (26 ) — Fair value, end of period $ 14,872 $ 14,238

Debt (Tables)

Debt (Tables)	3 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Scheduled Future Payments on Term Loan	The Company’s scheduled future payments on the SVB Term Loan at March 31, 2019 are as follows (in thousands): Year Ended December 31, The remainder of 2019 $ - 2020 1,555 2021 18,667 2022 18,667 2023 17,111 Total future principal payments 56,000 Less: unamortized debt discount (598 ) Carrying value of long-term debt 55,402 Less: current portion — Long-term portion $ 55,402

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
Schedule of Lease Costs and Cash Flow Transactions Arising From Lease Transactions	During the three months ended March 31, 2019, the Company recognized the following lease costs and cash flow transactions arising from lease transactions: Three Months Ended March 31, 2019 Operating lease cost $ 626 Cash paid for amounts included in the measurement of lease liabilities 514 Right-of-use assets obtained in exchange for new operating lease liabilities 492
Schedule of Future Minimum Payments and Interest Expense for Operating Leases	At March 31, 2019, the future payments and interest expense for the operating leases are as follows: Year Ending December 31, Future Payments The remainder of 2019 $ 1,584 2020 2,522 2021 2,567 2022 2,496 2023 2,571 2024 2,604 Thereafter 1,924 Total undiscounted cash flows $ 16,268 Less: imputed interest (3,493 ) Present value of lease liabilities $ 12,775
Schedule of Future Minimum Payments for Operating Leases	At December 31, 2018, the future minimum payments for the operating leases were as follows (in thousands): Year Ending December 31, Future Payments 2019 $ 2,070 2020 2,353 2021 2,424 2022 2,496 2023 2,571 Thereafter 4,532 Total future minimum payments $ 16,446

Revenue (Tables)

Revenue (Tables)	3 Months Ended
	Mar. 31, 2019
Revenue From Contract With Customer [Abstract]
Schedule of Revenue Disaggregated by Types and Geography	The following table presents revenue disaggregated by type and geography (in thousands): Three Months Ended March 31, 2019 2018 U.S. Product $ — $ 13,535 Service 634 396 Total U.S. revenue $ 634 $ 13,931 Outside of U.S. ("OUS") Product $ 18,874 $ 11,844 Service 657 296 Distribution rights 119 119 Total OUS revenue $ 19,650 $ 12,259 Total Product $ 18,874 $ 25,379 Service 1,291 692 Distribution rights 119 119 Total revenue $ 20,284 $ 26,190

Warrants (Tables)

Warrants (Tables)	3 Months Ended
	Mar. 31, 2019
Equity [Abstract]
Schedule of Key Terms of Placement Warrants	The key terms of the 2017 and 2016 Placement Warrants are as follows: Issuance Date Term Exercise Price Per Share Warrants Exercised during the Three Months Ended March 31, 2019 Warrants Outstanding at March 31, 2019 2017 Placement Warrants January 2017 7 years $ 3.17 6,022 1,703,510 2016 Placement Warrants August and September 2016 7 years $ 2.95 15,549 1,115,066 Total 21,571 2,818,576
Summary of Assumptions using Black- Scholes Option Pricing Model to estimate fair value	The fair value of the 2016 and 2017 Placement Warrants at March 31, 2019 and December 31, 2018, respectively, was estimated using the Black-Scholes option-pricing model and the following weighted-average assumptions: 2017 Placement Warrants 2016 Placement Warrants March 31, 2019 December 31, 2018 March 31, 2019 December 31, 2018 Expected term (in years) 4.8 5.1 4.4 4.7 Expected volatility 59.4% 60.8% 60.0% 60.9% Risk-free interest rate 2.2% 2.5% 2.2% 2.5% Expected dividend yield 0% 0% 0 0%

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Company's Stock Option Activity and Related Information	A summary of the Company’s stock option activity and related information is as follows: Options Outstanding Shares Available for Grant Number of Stock Options Outstanding Weighted- Average Exercise Price Weighted- Average Remaining Contractual Life (Years) Aggregate Intrinsic Value (In thousands) Balance at December 31, 2018 1,908,626 11,603,708 $ 6.64 7.6 $ 10,151 Additional options authorized 3,853,280 Options granted (1,872,022 ) 1,872,022 8.28 Options exercised - (588,120 ) 4.90 Options canceled 79,293 (79,293 ) 7.49 RSUs granted (651,392 ) Balance at March 31, 2019 3,317,785 12,808,317 $ 6.95 7.9 $ 16,290 Vested and exercisable at March 31, 2019 4,071,182 $ 4.32 5.9 $ 12,759 Vested and expected to vest at March 31, 2019 12,181,953 $ 6.89 7.9 $ 16,094
Schedule of Weighted-Average Assumptions Used in Black-Scholes Option-Pricing Model to Estimate Fair Value of Employee Stock Option at Grant Date	The fair value of employee stock option is estimated at the date of grant using a Black-Scholes option-pricing model with the following weighted-average assumptions: Three Months Ended March 31, 2019 2018 Expected term (in years) 6.0 5.9 Expected volatility% 60.4% 61.7% Risk-free interest rate% 2.6% 2.6% Expected dividend yield% 0.0% 0.0%
Summary of RSU Activity (Detail)	RSUs Number of Shares Weighted Average Grant Date Fair Value Unvested at December 31, 2018 1,736,234 $ 9.65 RSUs granted 651,392 7.69 RSUs vested (21,149 ) 6.33 Unvested at March 31, 2019 2,366,477 $ 9.14 Vested and unreleased 142,656 Outstanding at March 31, 2019 2,509,133
Summary of Stock-Based Compensation Expense	Total stock-based compensation expense recognized in the Company’s condensed consolidated statements of operations and comprehensive loss is classified as follows (in thousands): Three Months Ended March 31, 2019 2019 2018 Research and development $ 391 $ 203 Selling and marketing 265 127 General and administrative 3,896 860 Total stock-based compensation expense $ 4,552 $ 1,190

Net Loss per Share (Tables)

Net Loss per Share (Tables)	3 Months Ended
	Mar. 31, 2019
Earnings Per Share [Abstract]
Anti-Dilutive Securities Excluded from Calculation of Diluted Net Loss Per Share	Since the Company was in a loss position for all periods presented, diluted net loss per common share is the same as basic net loss per common share for all periods presented, because the inclusion of all potential common shares outstanding would have an anti-dilutive effect. The following weighted-average common stock equivalents were excluded from the calculation of diluted net loss per share for the periods presented, because including them would have an anti-dilutive effect: Three Months Ended March 31, 2019 2018 Series A convertible preferred stock (if converted) — 900,174 Options to purchase common stock 8,399,374 8,600,707 Common stock warrants 4,404,673 3,819,190 Restricted stock units 511,329 137,168 Total 13,315,376 13,457,239

Background and Organization - A

Background and Organization - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Net loss	$ (33,361)	$ (4,814)
Net cash used from operating activities	(23,653)	$ (37,454)
Cash and cash equivalents	$ 145,797		$ 167,432

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Significant Accounting Policies [Line Items]
Operating lease, right-of-use assets	$ 12,055,000		$ 0
Operating lease, liabilities	$ 12,775,000
ASU 2016-02
Significant Accounting Policies [Line Items]
Cumulative-effect adjustment recorded to retained deficit upon adoption		$ 0
Operating lease, right-of-use assets		11,900,000
Operating lease, liabilities		$ 12,600,000

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Property and Equipment, Net (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 33,916	$ 31,713
Less: accumulated depreciation and amortization	(18,637)	(17,755)
Property and equipment, net	15,279	13,958
Prototype
Property Plant And Equipment [Line Items]
Property and equipment, gross	12,247	12,425
Machinery and Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	13,871	12,654
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	4,621	4,600
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Property and equipment, gross	665	636
Software
Property Plant And Equipment [Line Items]
Property and equipment, gross	1,296	1,250
Construction in Progress
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 1,216	$ 148

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Balance Sheet Related Disclosures [Abstract]
Depreciation and amortization	$ 0.9	$ 0.7

Balance Sheet Components - Sc_2

Balance Sheet Components - Schedule of Accrued Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Payables And Accruals [Abstract]
Accrued payroll and related benefits	$ 5,828	$ 5,047
Accrued accounts payable	3,736	3,626
Payroll withholding tax, sales and other tax payable	439	782
Accrued legal, accounting and professional fees	721	360
Product upgrade reserve	4,964	0
Other	519	168
Total accrued liabilities	$ 16,207	$ 9,983

Balance Sheet Components - Sc_3

Balance Sheet Components - Schedule of Deferred Revenue (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Deferred Revenue [Line Items]
Total deferred revenue	$ 15,794	$ 19,475
Less: current portion of deferred revenue	(10,287)	(13,731)
Noncurrent portion of deferred revenue	5,507	5,744
Product
Deferred Revenue [Line Items]
Total deferred revenue	5,424	9,623
Service
Deferred Revenue [Line Items]
Total deferred revenue	7,618	6,981
Distribution Rights
Deferred Revenue [Line Items]
Total deferred revenue	$ 2,752	$ 2,871

Balance Sheet Components - Sc_4

Balance Sheet Components - Schedule of Other Long Term Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Payables And Accruals [Abstract]
Accrued interest, noncurrent portion	$ 104	$ 0
Deferred rent, noncurrent portion	0	628
Other	199	192
Total other-long term liabilities	$ 303	$ 820

Fair Value of Financial Instr_3

Fair Value of Financial Instruments - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Change in fair value of Level 3 financial liabilities	$ (3,120,000)	$ 8,182,000
Two Thousand Sixteen And Two Thousand Seventeen Private Placement Warrants
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Change in fair value of Level 3 financial liabilities	(3,000,000)	8,200,000
Transfers between Level 1 to Level 2	0	0
Transfers between Level 2 to Level 1	0	0
Transfers into or out of Level 3	$ 0	$ 0

Fair Value of Financial Instr_4

Fair Value of Financial Instruments - Schedule of Fair Value of Financial Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Warrant Liability	$ 14,872	$ 11,844
Fair Value Measurement on Recurring Basis
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Warrant Liability	14,872	11,844
Fair Value Measurement on Recurring Basis | 2017 Placement Warrants
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Warrant Liability	8,955	7,115
Fair Value Measurement on Recurring Basis | 2016 Placement Warrants
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Warrant Liability	5,917	4,729
Level 1 | Fair Value Measurement on Recurring Basis
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Warrant Liability	0	0
Level 1 | Fair Value Measurement on Recurring Basis | 2017 Placement Warrants
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Warrant Liability	0	0
Level 1 | Fair Value Measurement on Recurring Basis | 2016 Placement Warrants
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Warrant Liability	0	0
Level 2 | Fair Value Measurement on Recurring Basis
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Warrant Liability	0	0
Level 2 | Fair Value Measurement on Recurring Basis | 2017 Placement Warrants
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Warrant Liability	0	0
Level 2 | Fair Value Measurement on Recurring Basis | 2016 Placement Warrants
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Warrant Liability	0	0
Level 3 | Fair Value Measurement on Recurring Basis
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Warrant Liability	14,872	11,844
Level 3 | Fair Value Measurement on Recurring Basis | 2017 Placement Warrants
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Warrant Liability	8,955	7,115
Level 3 | Fair Value Measurement on Recurring Basis | 2016 Placement Warrants
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Warrant Liability	$ 5,917	$ 4,729

Fair Value of Financial Instr_5

Fair Value of Financial Instruments - Summary of Changes in Fair Value of Level 3 Financial Liabilities (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value, beginning of period	$ 11,844	$ 22,420
Change in fair value of Level 3 financial liabilities	3,120	(8,182)
Fair value, end of period	14,872	14,238
2016 Placement Warrants
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value of Placement Warrants at exercise	(66)	0
2017 Placement Warrants
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value of Placement Warrants at exercise	$ (26)	$ 0

Debt - Additional Information (

Debt - Additional Information (Detail) $ in Millions	1 Months Ended	3 Months Ended
	Dec. 31, 2018USD ($)Installment	Mar. 31, 2019USD ($)
SVB Term Loan
Debt Instrument [Line Items]
Total principal amout	$ 56
Debt maturity date	Dec. 1, 2023
Debt instrument interest rate percentage	6.30%
Frequency of periodic payment		monthly
Number of installments | Installment	36
Number of installments if achieving trailing revenue target and company so elects | Installment	30
Debt instrument description		Beginning on December 1, 2020 (or June 1, 2021, if the Company achieves a trailing twelve-month revenue of at least a specified amount and elects to apply such later date), the Company will make thirty-six equal monthly payments of principal (or thirty equal payments, if the Company so elects).
Final payment percentage of original principal amount	3.15%
Proceeds from term loan		$ 55.4
Legal and consulting fees		0.6
CRG Term Loan
Debt Instrument [Line Items]
Debt extinguishment loss		2.4
Write-off of unamortized debt discount and debt issuance costs		$ 0.3

Debt - Scheduled Future Payment

Debt - Scheduled Future Payments on Term Loan (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Long-term portion	$ 55,402	$ 55,364
SVB Term Loan
Debt Instrument [Line Items]
The remainder of 2019	0
2020	1,555
2021	18,667
2022	18,667
2023	17,111
Total future principal payments	56,000
Less: unamortized debt discount	(598)
Carrying value of long-term debt	55,402
Less: current portion	0
Long-term portion	$ 55,402

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) $ in Millions	1 Months Ended				3 Months Ended
	Apr. 30, 2019	Jun. 30, 2018	Apr. 30, 2018ft²	Jun. 30, 2014ft²	Mar. 31, 2019USD ($)ft²	Mar. 31, 2018USD ($)
Operating Leased Assets [Line Items]
Weighted-average remaining lease term					6 years 4 months 24 days
Weighted-average discount rate					7.70%
Rent expense | $						$ 0.2
Purchase commitments | $					$ 7.3
Lease Agreement | Oakwood Village, Ohio
Operating Leased Assets [Line Items]
Area of land | ft²					19,800
Lease agreement, expiration date					Oct. 31, 2019
Option to extend, description operating lease					extend the term of the lease agreement through October 2021
Lease Agreement | Mountain View, California
Operating Leased Assets [Line Items]
Area of land | ft²			24,600	25,500
Lease agreement, expiration date		Jul. 31, 2025	Dec. 31, 2025	Nov. 30, 2019
Option to extend, description operating lease		extend the term of the lease agreement through July 2025
Option to extend, existence operating Lease		true
Lease commencement date			2018-12
Lease Agreement | Mountain View, California | Maximum
Operating Leased Assets [Line Items]
Lease agreement, renewal term			5 years
Lease Agreement | Subsequent Event | Oakwood Village, Ohio
Operating Leased Assets [Line Items]
Option to extend, existence operating Lease	true
Lease agreement, option to extend expiration date	Oct. 31, 2021

Commitments and Contingencies_2

Commitments and Contingencies - Schedule of Lease Costs and Cash Flow Transactions Arising From Lease Transactions (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Commitments And Contingencies Disclosure [Abstract]
Operating lease cost	$ 626
Cash paid for amounts included in the measurement of lease liabilities	514
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 492	$ 0

Commitments and Contingencies_3

Commitments and Contingencies - Schedule of Future Minimum Payments and Interest Expense for Operating Leases (Detail) $ in Thousands	Mar. 31, 2019USD ($)
Operating Lease Liabilities Payments Due [Abstract]
The remainder of 2019	$ 1,584
2020	2,522
2021	2,567
2022	2,496
2023	2,571
2024	2,604
Thereafter	1,924
Total undiscounted cash flows	16,268
Less: imputed interest	(3,493)
Present value of lease liabilities	$ 12,775

Commitments and Contingencies_4

Commitments and Contingencies - Schedule of Future Minimum Payments for Operating Leases (Detail) $ in Thousands	Dec. 31, 2018USD ($)
Operating Leases Future Minimum Payments Due [Abstract]
2019	$ 2,070
2020	2,353
2021	2,424
2022	2,496
2023	2,571
Thereafter	4,532
Total future minimum payments	$ 16,446

Revenue - Summary of Revenue Di

Revenue - Summary of Revenue Disaggregated by Types and Geography (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disaggregation Of Revenue [Line Items]
Product, service and distribution rights revenue	$ 20,284	$ 26,190
Product
Disaggregation Of Revenue [Line Items]
Product, service and distribution rights revenue	18,874	25,379
Service
Disaggregation Of Revenue [Line Items]
Product, service and distribution rights revenue	1,291	692
Distribution Rights
Disaggregation Of Revenue [Line Items]
Product, service and distribution rights revenue	119	119
U.S.
Disaggregation Of Revenue [Line Items]
Product, service and distribution rights revenue	634	13,931
U.S. | Product
Disaggregation Of Revenue [Line Items]
Product, service and distribution rights revenue	0	13,535
U.S. | Service
Disaggregation Of Revenue [Line Items]
Product, service and distribution rights revenue	634	396
Outside of U.S. ("OUS")
Disaggregation Of Revenue [Line Items]
Product, service and distribution rights revenue	19,650	12,259
Outside of U.S. ("OUS") | Product
Disaggregation Of Revenue [Line Items]
Product, service and distribution rights revenue	18,874	11,844
Outside of U.S. ("OUS") | Service
Disaggregation Of Revenue [Line Items]
Product, service and distribution rights revenue	657	296
Outside of U.S. ("OUS") | Distribution Rights
Disaggregation Of Revenue [Line Items]
Product, service and distribution rights revenue	$ 119	$ 119

Revenue - Additional Informatio

Revenue - Additional Information (Detail)	Aug. 31, 2016	Dec. 31, 2014USD ($)Installment	Mar. 31, 2019USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2018USD ($)
Revenues [Line Items]
Distribution fees			$ 20,284,000	$ 26,190,000
Long-term trade receivables			$ 400,000		$ 400,000
Long-term trade credit maintenance services term			1 year
Allowance for doubtful accounts			$ 0		$ 0
Deferred revenue, recognized			7,900,000	22,200,000
Company recognized revenue from performance obligations satisfied in the prior period			$ 900,000
Minimum
Revenues [Line Items]
Expected long-term trade receivables collection period			3 years
Maximum
Revenues [Line Items]
Expected long-term trade receivables collection period			4 years
Itochu Corporation Agreement
Revenues [Line Items]
Number of installments | Installment		3
Remaining term of distribution agreement	8 years 6 months
Itochu Corporation Agreement | Distribution Rights
Revenues [Line Items]
Distribution fees		$ 4,000,000	$ 100,000	$ 100,000

Equity Financing - Additional I

Equity Financing - Additional Information (Detail) - USD ($)	Aug. 17, 2018	Aug. 14, 2018	Feb. 28, 2018	Jan. 31, 2017	Sep. 30, 2016	Mar. 31, 2019	Jan. 31, 2019	Dec. 31, 2018	Apr. 30, 2017
Subsidiary Sale Of Stock [Line Items]
Common stock sold						$ 959,000		$ 952,000
2017 Placement Warrants
Subsidiary Sale Of Stock [Line Items]
Warrants to purchase common stock, shares				1,720,512
Warrant exercise price				$ 3.17		$ 3.17
Warrant expiration date				Jan. 31, 2024
Warrant exercisable date				Jul. 31, 2017
Warrant expiration period				7 years
2016 Placement Warrants
Subsidiary Sale Of Stock [Line Items]
Warrants to purchase common stock, shares					1,380,745
Warrant exercise price					$ 2.95	$ 2.95
Warrant expiration period					7 years	7 years
Underwriters | Common Stock
Subsidiary Sale Of Stock [Line Items]
Underwriting agreement date		Aug. 14, 2018
Number of shares issued in transaction		16,216,217
Sale of stock, price		$ 9.25
Option to purchase additional shares		30 days
Aggregate proceeds from issuance of common stock	$ 161,900,000
Underwriters | Common Stock | Maximum
Subsidiary Sale Of Stock [Line Items]
Number of additional shares issued in transaction		2,432,432
March 2018 Direct Registered Offering
Subsidiary Sale Of Stock [Line Items]
Proceed from private placement and equity issuances, gross			$ 59,100,000
March 2018 Direct Registered Offering | Common Stock
Subsidiary Sale Of Stock [Line Items]
Stock issued during period			4,090,000
March 2018 Direct Registered Offering | Series A Convertible Preferred Stock
Subsidiary Sale Of Stock [Line Items]
Stock issued during period			3,000,581
March 2018 Direct Registered Offering Warrants
Subsidiary Sale Of Stock [Line Items]
Warrants to purchase common stock, shares			1,418,116
Warrant exercise price			$ 8.31
Warrant expiration date			Mar. 31, 2025
2017 Private Placement | Common Stock
Subsidiary Sale Of Stock [Line Items]
Number of shares issued in transaction				8,602,589
Proceed from private placement and equity issuances, gross				$ 26,100,000
2016 Private Placement | Common Stock
Subsidiary Sale Of Stock [Line Items]
Number of shares issued in transaction					4,602,506
Proceed from private placement and equity issuances, gross					$ 13,800,000
At The Market Offering Program
Subsidiary Sale Of Stock [Line Items]
Stock issued during period						0
Common stock sold						$ 40,400,000
At The Market Offering Program | Maximum
Subsidiary Sale Of Stock [Line Items]
Maximum aggregate offering price				$ 75,000,000			$ 250,000,000
Maximum common stock saleable shares, value							$ 100,000,000		$ 50,000,000

Warrants - Additional Informati

Warrants - Additional Information (Detail) $ / shares in Units, $ in Thousands	Mar. 30, 2019shares	Aug. 31, 2015$ / sharesshares	Jul. 31, 2015$ / sharesshares	Mar. 31, 2019USD ($)shares	Mar. 31, 2018USD ($)$ / sharesshares	Dec. 31, 2013$ / sharesshares
Common Stock Warrants [Line Items]
Placement warrants not excercised and remained outstanding				2,818,576
(Gain) loss related to change in fair value | $				$ 3,120	$ (8,182)
2018 Direct Registered Offering | Common Stock
Common Stock Warrants [Line Items]
Warrants issued					1,418,116
Exercise price | $ / shares					$ 8.31
Common stock warrants, expiration date					Mar. 31, 2025
Proceed from private placement and equity issuances, gross | $					$ 59,100
Fair value of warrants upon issuance | $					$ 7,400
Warrants, fair value measurement inputs					7 years
Allocated portion of proceeds from issuance of stock and warrants | $					$ 6,600
2018 Direct Registered Offering | Common Stock | Expected Volatility
Common Stock Warrants [Line Items]
Warrants, fair value measurement inputs					0.625
2018 Direct Registered Offering | Common Stock | Risk-free Interest Rate
Common Stock Warrants [Line Items]
Warrants, fair value measurement inputs					0.028
2018 Direct Registered Offering | Common Stock | Expected Dividend Yield
Common Stock Warrants [Line Items]
Warrants, fair value measurement inputs					0
Equity Classified Common Stock Warrants
Common Stock Warrants [Line Items]
Warrants issued						128,231
Exercise price | $ / shares						$ 5.84
Common stock warrants, expiration date				Dec. 16, 2023
2015 Placement Equity Classified Common Stock Warrants | Insiders
Common Stock Warrants [Line Items]
Warrants issued		198,760	198,760
Exercise price | $ / shares		$ 5	$ 5
Warrant expiration period		5 years	5 years
Number of warrant exercised	159,010
Stock issued during period	92,487
Placement warrants not excercised and remained outstanding				39,750
2016 and 2017 Placement Warrants | Common Stock
Common Stock Warrants [Line Items]
(Gain) loss related to change in fair value | $				$ 3,000	$ (8,200)

Warrants - Schedule of Key Term

Warrants - Schedule of Key Terms of Placement Warrants (Detail) - $ / shares	1 Months Ended		3 Months Ended
	Jan. 31, 2017	Sep. 30, 2016	Mar. 31, 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Warrants Exercised			21,571
Warrants Outstanding			2,818,576
2017 Placement Warrants
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Issuance Date			2017-01
Term	7 years
Exercise Price Per Share	$ 3.17		$ 3.17
Warrants Exercised			6,022
Warrants Outstanding			1,703,510
2016 Placement Warrants
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Issuance Date			2016-08
Issuance Date			2016-09
Term		7 years	7 years
Exercise Price Per Share		$ 2.95	$ 2.95
Warrants Exercised			15,549
Warrants Outstanding			1,115,066

Warrants - Summary of Assumptio

Warrants - Summary of Assumptions to Use Option Pricing Model (Detail)	Mar. 31, 2019	Dec. 31, 2018
2017 Placement Warrants | Expected Term
Fair Value Inputs1 Liabilities Quantitative Information [Line Items]
Expected term (in years)	4 years 9 months 18 days	5 years 1 month 6 days
2017 Placement Warrants | Expected Volatility
Fair Value Inputs1 Liabilities Quantitative Information [Line Items]
Warrants, fair value measurement inputs	0.594	0.608
2017 Placement Warrants | Risk-free Interest Rate
Fair Value Inputs1 Liabilities Quantitative Information [Line Items]
Warrants, fair value measurement inputs	0.022	0.025
2017 Placement Warrants | Expected Dividend Yield
Fair Value Inputs1 Liabilities Quantitative Information [Line Items]
Warrants, fair value measurement inputs	0	0
2016 Placement Warrants | Expected Term
Fair Value Inputs1 Liabilities Quantitative Information [Line Items]
Expected term (in years)	4 years 4 months 24 days	4 years 8 months 12 days
2016 Placement Warrants | Expected Volatility
Fair Value Inputs1 Liabilities Quantitative Information [Line Items]
Warrants, fair value measurement inputs	0.600	0.609
2016 Placement Warrants | Risk-free Interest Rate
Fair Value Inputs1 Liabilities Quantitative Information [Line Items]
Warrants, fair value measurement inputs	0.022	0.025
2016 Placement Warrants | Expected Dividend Yield
Fair Value Inputs1 Liabilities Quantitative Information [Line Items]
Warrants, fair value measurement inputs	0	0

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Company's Stock Option Activity and Related Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Shares Available for Grant
Shares Available for Grant, Beginning balance	1,908,626
Shares Available for Grant, Additional options authorized	3,853,280
Shares Available for Grant, Options granted	(1,872,022)
Shares Available for Grant, Options canceled	79,293
Shares Available for Grant, Ending balance	3,317,785	1,908,626
Shares Available for Grant, RSUs granted	(651,392)
Number of Stock Options Outstanding
Number of Stock Options Outstanding, Beginning balance	11,603,708
Number of Stock Options Outstanding, Options granted	1,872,022
Number of Stock Options Outstanding, Options exercised	(588,120)
Number of Stock Options Outstanding, Options canceled	(79,293)
Number of Stock Options Outstanding, Ending balance	12,808,317	11,603,708
Number of Stock Options Outstanding, Vested and exercisable	4,071,182
Number of Stock Options Outstanding, Vested and expected to vest	12,181,953
Weighted- Average Exercise Price
Weighted- Average Exercise Price, Beginning balance	$ 6.64
Weighted- Average Exercise Price, Options granted	8.28
Weighted- Average Exercise Price, Options exercised	4.90
Weighted- Average Exercise Price, Options canceled	7.49
Weighted- Average Exercise Price, Ending balance	6.95	$ 6.64
Weighted- Average Exercise Price, Vested and exercisable	4.32
Weighted- Average Exercise Price, Vested and expected to vest	$ 6.89
Weighted- Average Remaining Contractual Life (Years)
Options Outstanding, Weighted- Average Remaining Contractual Life (Years)	7 years 10 months 24 days	7 years 7 months 6 days
Weighted- Average Remaining Contractual Life (Years), Vested and exercisable	5 years 10 months 24 days
Weighted- Average Remaining Contractual Life (Years), Vested and expected to vest	7 years 10 months 24 days
Aggregate Intrinsic Value
Aggregate Intrinsic Value	$ 16,290	$ 10,151
Aggregate Intrinsic Value, Vested and exercisable	12,759
Aggregate Intrinsic Value, Vested and expected to vest	$ 16,094

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted average grant date fair value of options granted, per share	$ 4.78	$ 4.75
Grant date fair value of options vested	$ 1,200,000	$ 1,100,000
Aggregate intrinsic value of options exercised	1,900,000	1,600,000
Unrecognized compensation cost	$ 34,100,000
Weighted average period for recognition of compensation costs	3 years 2 months 12 days
RSUs Granted	651,392
RSUs Vested	21,149
Stock-based compensation expense capitalized	$ 0	$ 0
Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted average period for recognition of compensation costs	2 years 3 months 18 days
Total grant date fair value of RSUs	$ 5,000,000
Total fair value of RSUs vested	100,000
RSUs Granted		0
RSUs Vested		0
Unrecognized stock based compensation cost	$ 16,200,000
Shares expected to vest	2,191,333

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Weighted-Average Assumptions Used in Black-Scholes Option-Pricing Model to Estimate Fair Value of Employee Stock Option at Grant Date (Detail)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Expected term (in years)	6 years	5 years 10 months 24 days
Expected volatility%	60.40%	61.70%
Risk-free interest rate%	2.60%	2.60%
Expected dividend yield%	0.00%	0.00%

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of RSU Activity (Detail)	3 Months Ended
	Mar. 31, 2019$ / sharesshares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Unvested at December 31, 2018, Number of Shares	1,736,234
RSUs granted, Number of Shares	651,392
RSUs vested, Number of Shares	(21,149)
Unvested at March 31, 2019, Number of Shares	2,366,477
Vested and unreleased, Number of Shares	142,656
Outstanding at March 31, 2019, Number of Shares	2,509,133
Unvested at December 31, 2018, Weighted Average Grant Date Fair Value | $ / shares	$ 9.65
RSUs granted, Weighted Average Grant Date Fair Value | $ / shares	7.69
RSUs vested, Weighted Average Grant Date Fair Value | $ / shares	6.33
Unvested at March 31, 2019, Weighted Average Grant Date Fair Value | $ / shares	$ 9.14

Stock-Based Compensation - Su_3

Stock-Based Compensation - Summary of Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 4,552	$ 1,190
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	391	203
Selling and Marketing
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	265	127
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 3,896	$ 860

Income Tax - Additional Informa

Income Tax - Additional Information (Detail) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income tax expense	$ 0	$ 0
Federal and state effective tax rate before valuation allowance	24.00%
Unrecognized tax benefits	$ 2,100,000		$ 1,600,000
Accrued interest and penalties related to uncertain tax positions	$ 0		$ 0

Net Loss Per Share - Anti-Dilut

Net Loss Per Share - Anti-Dilutive Securities Excluded from Calculation of Diluted Net Loss Per Share (Detail) - shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net loss per share	13,315,376	13,457,239
Series A Convertible Preferred Stock (If Converted)
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net loss per share	0	900,174
Options To Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net loss per share	8,399,374	8,600,707
Common Stock Warrants
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net loss per share	4,404,673	3,819,190
Restricted Stock Units (RSUs)
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net loss per share	511,329	137,168

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail) - USD ($)	1 Months Ended		3 Months Ended
	Jan. 31, 2017	Dec. 31, 2014	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2004
Related Party Transaction [Line Items]
Percentage of royalty expense based on net sales			1.00%
Cost of Revenue
Related Party Transaction [Line Items]
Royalty Expense			$ 200,000	$ 0
University Of Florida Research Foundation | Licensing Agreements
Related Party Transaction [Line Items]
Common Stock granted in exchange for licensing		33,652
Percentage of royalty payment based on sale					1.00%
Royalty payment per quarter		$ 100,000
Investment Manager of Investment Company | Sales Consulting Agreement [Member]
Related Party Transaction [Line Items]
Related party, agreement term	1 year
Related party, total consideration	$ 1,300,000