Aquantia 10-K 6 Mar 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Feb. 28, 2019	Jun. 29, 2018
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Trading Symbol	AQ
Entity Registrant Name	AQUANTIA CORP
Entity Central Index Key	1,316,016
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Public Float			$ 214,546,736
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Shell Company	false
Entity Small Business	false
Entity Common Stock, Shares Outstanding		35,174,345

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 6,684	$ 8,040
Short-term investments	60,730	48,362
Accounts receivable	16,927	15,012
Inventories	14,474	18,469
Prepaid expenses and other current assets	2,018	5,623
Total current assets	100,833	95,506
Property and equipment, net	9,225	9,973
Intangible assets, net	3,748	4,556
Other assets	617	331
Total assets	114,423	110,366
Current liabilities:
Accounts payable	5,495	7,059
Accrued liabilities	13,907	9,217
Total current liabilities	19,402	16,276
Other long-term liabilities	1,799	3,176
Total liabilities	21,201	19,452
Commitments and contingencies (Note 6)
Stockholders’ equity:
Preferred stock, $0.00001 par value, 5,000,000 and 10,000,000 shares authorized as of December 31, 2018 and 2017, respectively; zero share outstanding at December 31, 2018 and 2017, respectively
Additional paid-in capital	300,791	288,719
Accumulated other comprehensive loss	(123)	(96)
Accumulated deficit	(207,446)	(197,709)
Total stockholders’ equity	93,222	90,914
Total liabilities and stockholders’ equity	$ 114,423	$ 110,366

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2018	Dec. 31, 2017
Statement Of Financial Position [Abstract]
Preferred stock, par value	$ 0.00001	$ 0.00001
Preferred stock, shares authorized	5,000,000	10,000,000
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.00001	$ 0.00001
Common stock, shares authorized	95,000,000	400,000,000
Common stock, shares issued	35,050,425	33,523,683
Common stock, shares outstanding	35,050,425	33,523,683

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Statement [Abstract]
Revenue	$ 120,784	$ 103,371	$ 86,675
Cost of revenue	52,395	44,348	34,064
Gross profit	68,389	59,023	52,611
Operating expenses:
Research and development	56,023	44,763	36,553
Sales and marketing	10,117	7,235	5,347
General and administrative	12,754	9,975	7,124
Total operating expenses	78,894	61,973	49,024
Income (loss) from operations	(10,505)	(2,950)	3,587
Other income (expense):
Other income, net	1,208	141	14
Interest expense		(1,735)	(3,334)
Change in fair value of convertible preferred stock warrant liability		(990)	(544)
Total other income (expense)	1,208	(2,584)	(3,864)
Loss before income tax expense	(9,297)	(5,534)	(277)
Provision for (benefit from) income taxes	475	(117)	168
Net loss	$ (9,772)	$ (5,417)	$ (445)
Net loss per share, basic and diluted	$ (0.29)	$ (0.59)	$ (0.10)
Weighted-average shares used to compute net loss per share, basic and diluted	34,181,200	9,204,384	4,240,461
Comprehensive income (loss):
Net loss	$ (9,772)	$ (5,417)	$ (445)
Other comprehensive income (loss), net of tax:
Unrealized gains and losses - short-term investments	(27)	(96)
Comprehensive loss	$ (9,799)	$ (5,513)	$ (445)

CONSOLIDATED STATEMENTS OF CONV

CONSOLIDATED STATEMENTS OF CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) - USD ($) $ in Thousands	Total	Convertible Preferred Stock	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive loss	Accumulated Deficit
BALANCE, Temporary Equity, Shares at Dec. 31, 2015		19,791,207
BALANCE, Temporary Equity at Dec. 31, 2015		$ 199,153
BALANCE, Shares at Dec. 31, 2015			1,984,518
BALANCE at Dec. 31, 2015	$ (184,887)			$ 6,894		$ (191,781)
Exercise of stock options, shares			2,459,180
Exercise of stock options	4,586			4,586
Issuance of Series A/H convertible preferred stock upon exercise of warrants, shares		33,493
Issuance of Series A/H convertible preferred stock upon exercise of warrants		$ 281
Stock-based compensation expense	939			939
Net loss	(445)					(445)
BALANCE, Temporary Equity, Shares at Dec. 31, 2016		19,824,700
BALANCE, Temporary Equity at Dec. 31, 2016		$ 199,434
BALANCE at Dec. 31, 2016	(179,807)			12,419		(192,226)
BALANCE, Shares at Dec. 31, 2016			4,443,698
Cumulative effect upon adoption of ASU 2016-09/ ASC 606				66		(66)
Other comprehensive loss - unrealizedloss on short-term investments	(96)				$ (96)
Exercise of stock options, shares			388,621
Exercise of stock options	1,272			1,272
Issuance of restricted stock units			35,029
Repurchase of unvested stock, shares			(1,119)
Repurchase of unvested stock	(3)			(3)
Issuance of Series A/H convertible preferred stock upon exercise of warrants, shares		975,616
Issuance of Series A/H convertible preferred stock upon exercise of warrants		$ 10,835
Proceeds from initial public offering, net of issuance costs, shares			7,840,700
Proceeds from initial public offering, net of issuance costs	59,886			59,886
Conversion of preferred stock to common stock pursuant to IPO, shares		(20,800,316)	20,816,754
Conversion of preferred stock to common stock pursuant to IPO	210,269	$ (210,269)		210,269
Conversion of preferred stock warrants to common stock warrants	3,137			3,137
Stock-based compensation expense	1,673			1,673
Net loss	(5,417)					(5,417)
BALANCE at Dec. 31, 2017	$ 90,914			288,719	(96)	(197,709)
BALANCE, Shares at Dec. 31, 2017	33,523,683		33,523,683
Cumulative effect upon adoption of ASU 2016-09/ ASC 606	$ 35					35
Other comprehensive loss - unrealizedloss on short-term investments	(27)				(27)
Exercise of stock options, shares			825,150
Exercise of stock options	2,793			2,793
ESPP Purchase	2,972			2,972
ESPP Purchase, shares			366,369
Issuance of restricted stock units			24,929
Repurchase of stock options	(32)			(32)
Repurchase of stock options, shares			(8,649)
Issuance of common stock, net upon exercise of warrants			318,943
IPO Costs	(181)			(181)
Stock-based compensation expense	6,520			6,520
Net loss	(9,772)					(9,772)
BALANCE at Dec. 31, 2018	$ 93,222			$ 300,791	$ (123)	$ (207,446)
BALANCE, Shares at Dec. 31, 2018	35,050,425		35,050,425

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities
Net loss	$ (9,772)	$ (5,417)	$ (445)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	5,822	4,720	2,740
Stock-based compensation expense	6,520	1,673	939
Accretion of investment premium, net of amortization of discount	(244)
(Gain) loss on disposal of property and equipment	(70)		33
Change in fair value of convertible preferred stock warrant liability		990	544
Amortization of debt discount and extinguishment cost		477	636
Non-cash interest expense related to debt costs		175	552
Changes in operating assets and liabilities:
Accounts receivable	(1,915)	(3,517)	(4,443)
Inventories	3,995	(11,452)	9,570
Prepaid expenses and other assets	3,319	(4,110)	1,617
Accounts payable	(1,231)	2,139	2,198
Accrued and other liabilities	3,631	2,813	256
Deferred revenue			(2,059)
Net cash provided by (used in) operating activities	10,055	(11,509)	12,138
Cash flows from investing activities
Purchases of property and equipment	(4,599)	(5,585)	(6,308)
Purchases of IP licenses			(2,129)
Proceeds from sale of PP&E	70		6
Proceeds from sales of short-term investments	2,000
Proceeds from maturities of short-term investments	43,573	1,850
Purchases of short-term investments	(57,724)	(50,308)
Net cash used in investing activities	(16,680)	(54,043)	(8,431)
Cash flows from financing activities
Repayments on short and long-term borrowings		(19,161)	(6,560)
Repayments on line of credit		(10,000)	(5,001)
Proceeds from line of credit		10,000
Proceeds from exercise of stock options and preferred stock warrants	2,761	1,368	4,861
Proceeds from employee stock purchase plan	2,972
Purchases of IP licenses	(26)	(260)
Proceeds from initial public offering		65,627
Payment of costs related to initial public offering	(438)	(2,875)	(2,404)
Net cash provided by (used in) financing activities	5,269	44,699	(9,104)
Net decrease in cash and cash equivalents	(1,356)	(20,853)	(5,397)
Cash and cash equivalents at beginning of period	8,040	28,893	34,290
Cash and cash equivalents at end of period	6,684	8,040	28,893
Supplemental disclosures of cash flow information
Cash paid for interest	25	1,153	1,972
Cash paid for income taxes	285	232	333
Non-cash financing and investing transactions
Reclassification of fair value of warrants to equity from liabilities upon warrant exercise and IPO		13,875
Unpaid costs related to initial public offering		254	340
Property and equipment received and accrued	$ 86	419	240
IP licenses accrued			$ 3,286
Transfer of deferred IPO cost to equity upon IPO		$ 5,740

Organization, Description of Bu

Organization, Description of Business and Basis for Presentation	12 Months Ended
	Dec. 31, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization, Description of Business and Basis for Presentation	1. Organization, Description of Business and Basis for Presentation Organization —Aquantia Corp. (together with its subsidiaries, the “Company”) was incorporated in Delaware on January 27, 2004. The Company is a leader in the design, development and marketing of advanced high-speed communications integrated circuits, or ICs, for Ethernet connectivity in the data center, enterprise infrastructure, access and automotive markets. Initial Public Offering — On November 7, 2017, the Company completed its initial public offering, or IPO, of 7,840,700 shares of its common stock at the offering price of $9.00 per share, including 1,022,700 shares pursuant to the underwriters’ option to purchase additional shares of the Company’s common stock, resulting in net proceeds to the Company of $65.6 million after deducting underwriters' discounts and commissions of $4.9 million, but before deducting total offering expenses of $5.7 million which were reclassified to additional paid-in capital upon completion of the IPO. Immediately prior to the closing of the IPO, all outstanding shares of the Company’s convertible preferred stock automatically converted into shares of its common stock and the Company’s convertible preferred stock warrants automatically converted into warrants to purchase common stock. The Company used $9.2 million and $0.3 million of the IPO proceeds, respectively, to repay the outstanding indebtedness under the Company’s loan from Pinnacle Ventures, L.L.C. and the termination fee for the line of credit from Hercules. Reverse Stock Split — In September 2017, the Company’s board of directors and stockholders approved a 1-for-10 reverse split of the Company’s common stock (the “Reverse Stock Split”), which was effected on October 5, 2017. The board of directors and stockholders also approved proportionate adjustments to the conversion prices of each series of convertible preferred stock and convertible preferred stock warrants. All share and per share information included in the accompanying consolidated financial statements and notes thereto have been adjusted to reflect the Reverse Stock Split. Basis of Presentation and Principles of Consolidation— The consolidated financial statements are prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) and include the consolidated accounts of the Company and its wholly-owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. Liquidity and Capital Resources — As shown in the consolidated financial statements, the Company has incurred net losses from inception through December 31, 2018, resulting in an accumulated deficit of approximately $207.4 million. The Company has financed its operations primarily from cash received from product sales, IPO, sales of convertible preferred stock, and debt financing before the IPO. Based on expected cash flows, the Company believes that its existing cash will be sufficient to satisfy its anticipated cash requirements for the next 12 months.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Use of Estimates —The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the consolidated financial statements, and the reported amounts of expenses during the reporting period. Significant estimates used in the preparation of the consolidated financial statements include revenue recognition, the valuation of deferred tax assets, uncertain tax positions, and useful lives of long-lived assets. These estimates and the underlying assumptions are based on management’s best estimates and judgment. Management evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors and adjusts such estimates and assumptions when facts and circumstances dictate. As future events and their effects cannot be determined with precision, actual results could differ significantly from these estimates. Financial Instruments —Financial instruments held by the Company consist primarily of corporate bonds, U.S. government securities, commercial paper and money market funds. The Company considers all highly liquid financial instruments purchased with an original maturity or remaining maturities of three months or less at the date of purchase to be cash equivalents. All remaining financial instruments are classified as short-term investments. The Company’s financial instruments are classified as available-for-sale. Unrealized gains and losses on securities, net of tax, are recorded in accumulated other comprehensive loss and reported as a separate component of stockholders’ equity. Interest and dividend income and realized gains or losses are included in other income, net on the consolidated statements of operations and comprehensive loss. The Company evaluates the investments periodically for possible other-than-temporary impairment and reviews factors such as the length of time and extent to which fair value has been below cost basis, the financial condition of the issuer, the Company’s intent to hold and whether the Company will not be required to sell the security before its anticipated recovery, on a more-likely-than-not basis. If the declines in the fair value of the investments are determined to be other-than-temporary, the Company reports the credit loss portion of such decline in other income, net and the remaining noncredit loss portion in accumulated other comprehensive loss. The cost of securities sold is based on the specific identification method. Accounts Receivable —The Company’s receivables are recorded when due and payable. The carrying value of the accounts receivable represents their estimated net realizable value which is reduced by an allowance for doubtful accounts that reflects management’s best estimate of amounts that will not be collected. Based on historical loss experience has been negligible, no allowance for doubtful account has been charged against accounts receivable in the periods presented. Inventories —Inventories consist of processed wafers, work-in-process and finished goods and are stated at the lower of standard cost or net realizable value. Standard costs approximate actual costs and are based on a first-in, first-out basis. The Company performs detailed reviews of the net realizable value of inventories, both on hand as well as for inventories that it is committed to purchase and writes down the inventory value for estimated deterioration, excess and obsolete and other factors based on management’s assessment of future demand and market conditions. Once written down, inventory write downs are not reversed until the inventory is sold or scrapped. For each of the year ended December 31, 2018 and 2017, inventory write-downs were negligible. Deferred Initial Public Offering Costs —Deferred initial public offering costs, consisting of direct and incremental legal, accounting and other fees and costs attributable to the Company’s IPO and the preparation of the related registration statement, are capitalized. The total deferred offering costs of $5.7 million were offset against the proceeds received upon the closing of the IPO. Property and Equipment —Property and equipment is initially recorded at cost and depreciated using the straight-line method over the estimated useful lives of the assets. Leasehold improvements are amortized over the estimated useful life or the original lease term, whichever is shorter. Intangible Assets —Intangible assets consist of patents and IP license and are amortized over their useful lives of 7-12 years using a straight-line amortization method. Impairment of Long-Lived Assets —Long-lived assets, such as property and equipment and intangible assets, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to estimated undiscounted future cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated future cash flows, an impairment charge is recognized in the amount by which the carrying amount of the asset exceeds the undiscounted future cash flows. The Company has not recorded any impairment charges in any of the periods presented. Product Warranty —The Company’s products are generally sold with a limited standard warranty for a period of one to three years, warranting that the product conforms to specifications and is free from material defects in design, materials and workmanship. To date, the Company has had negligible returns of any defective production parts Convertible Preferred Stock Warrant Liability —The Company accounted for its convertible preferred stock warrants outstanding prior to the IPO as derivative liabilities as the terms of the warrants were not fixed due to potential adjustments in the exercise price and the number of shares upon an equity financing at a lower price. The convertible preferred stock warrants were initially recorded at fair value when issued, with gains and losses arising from changes in fair value recognized in other income (expense) in the consolidated statements of operations and comprehensive loss at each period end while such instruments were outstanding and classified as liabilities. The fair values of the convertible preferred stock warrants issued in connection with debt agreements were recorded as debt discounts and were amortized as non-cash interest expense in the consolidated statement of operations over the expected term of the debt agreements. Upon the exercise of the warrants, the liability was reclassified to convertible preferred stock at its then fair value. Upon the completion of the IPO in November 2017, the warrants were converted into warrants to purchase shares of common stock and the liability was reclassified to stockholders’ equity at their then fair value, and was no longer subject to fair value accounting. Convertible Preferred Stock —Prior to the IPO, the Company recorded convertible preferred stock at fair value on the dates of issuance, net of issuance costs. The convertible preferred stock is recorded outside of stockholders’ equity because the shares contain liquidation features that were not solely within the Company’s control. The Company has elected not to adjust the carrying values of the convertible preferred stock to the liquidation preferences of such shares because it was uncertain whether or when an event would occur that would obligate the Company to pay the liquidation preferences to holders of shares of convertible preferred stock. Subsequent adjustments to the carrying values to the liquidation preferences were made only when it becomes probable that such a liquidation event will occur. In November 2017, all outstanding convertible preferred stock was converted to common stock and the balance of convertible preferred stock was reclassified to additional paid in capital upon the closing of the IPO. Revenue Recognition — Product revenues consist of sales to customers which are mainly comprised of end customers, their manufacturing subcontractors, and distributors. Revenue is recognized after the Company (a) identifies the contract with a customer, (b) identifies the performance obligations in the contract, (c) determines the transaction price, (d) allocates the transaction price to the performance obligations in the contract, and (e) satisfies the performance obligation when the control of products is transferred to the customer. The Company considers the purchase orders, which in some cases are governed by master sales agreements, to be the contract with its customers. In evaluating the existence of the contract, the Company considers various factors relative to the contract including the customer’s ability to pay amounts due under the contract. The Company is obligated to deliver a fixed number of products to its customers, each of which is distinct, and have been separately identified to be the performance obligations. The Company generally provides an assurance warranty that its products will substantially conform to the published specifications for twelve months from the date of shipment. The Company has not provided services in addition to the standard warranty. As such, the Company does not consider activities related to such warranty, if any, to be a separate performance obligation. In determining the transaction price, the Company considers the variability of the amount due under the contract including amounts subject to refund or adjustment when determining the net consideration to which the Company expects to be entitled within the contract. As the Company’s standard payment terms are less than one year, the Company has elected the practical expedient under the accounting guidance and does not assess whether the contract has a significant financing component. The Company allocates revenue to each product based on their relative standalone selling price. Frequently, the Company receives orders for products to be delivered over multiple dates that may extend across several reporting periods. The Company invoices for each delivery upon shipment and recognizes revenues for each distinct product delivered, assuming transfer of control has occurred. As scheduled delivery dates are within one year, under the optional exemption revenues allocated to future shipments of partially completed contracts are not disclosed. The Company has also elected the practical expedient under ASC 340-40-25-4, “ Other Assets and Deferred Costs”, Sales to certain of end customers include limited rebates. The Company estimates these rebates, using historical volumes of such rebates, at the time revenue is recognized. Such rebates were not significant in any of the periods presented, and the differences between the actual amount of such rebates and our estimates also were not significant. Sales to most of our distributors are made under contracts that allow for pricing credits upon shipment to the end customer and rights of return for on hand inventory at the distributor. Under the accounting guidance, revenue is recognized at the point of transfer of control to the distributor, which typically occurs at the point of shipment. The Company adjusts the transaction price for any unprocessed claims and for future estimated pricing credits which is recorded in accrued liabilities on the consolidated balance sheets. The adjustments for these estimates are recorded as a reduction to revenue in the same period when the related revenue is recorded and is calculated based on an analysis of the historical actual claims received, both in aggregate and at a distributor level to the extent that it is probable that a significant future reversal of revenue will not occur. Historically, adjustments for actual pricing credits and product returns have not been significantly differed from the amounts estimated by the Company. As of December 31, 2018, the Company has recorded an accrued liability of $0.3 million related to the above adjustments to transaction price. Cost of Revenue —Cost of revenue consists of wafers, processed by third-party foundries, costs associated with packaging, assembly, and test paid to third-party contract manufacturers, and personnel and other costs associated with the Company’s manufacturing operations. Cost of revenue also includes allocation of overhead and facility costs, depreciation of production equipment, inventory write-downs and amortization of production mask costs. Research and Development —Research and development expenses are charged to operations as incurred. These costs include personnel costs, pre-production engineering mask costs, software license and intellectual property expenses, design tools and prototype-related expenses, facility costs, supplies and depreciation expense. The Company enters into development agreements with some of its customers that provide fees that partially offset development costs. Such fees are recognized upon completion of the contract deliverables or milestones, and acceptance by the customer, if required. Income Taxes —Deferred tax assets and liabilities are recognized for the expected future tax consequences of temporary differences between the financial statements’ carrying amounts of existing assets and liabilities and their respective tax basis and net operating loss and tax credit carryforwards. Valuation allowances are established when necessary to reduce deferred tax assets to the amount expected to be realized. A tax position is recognized only if it is more likely than not to be sustained based solely on its technical merits as of the reporting date and then only in an amount more likely than not to be sustained upon review by the tax authorities. The Company considers many factors when evaluating and estimating its tax positions and tax benefits, which may require periodic adjustments and which may not accurately represent actual outcomes. Stock-Based Compensation —Compensation expense related to stock-based transactions is measured and recognized in the financial statements at fair value. Stock-based compensation expense is measured at the grant date based on the fair value of the equity award and is recognized as expense, less actual forfeitures (see Note 7), over the requisite service period, which is generally the vesting period on the straight-line method. The Company estimates the fair value of each stock option award on the date of grant using the Black-Scholes option-pricing model. Determining the fair value of stock option awards at the grant date requires judgment, including estimating the common stock fair value, expected term, expected volatility, risk-free interest rate, and expected dividends. The Company accounts for equity instruments issued to nonemployees based on the fair value of the awards determined using the Black-Scholes option pricing model. The fair value of such instruments is recognized as an expense over the vesting period. Other Comprehensive Loss —As of December 31, 2018 and 2017, the Company purchased financial instruments which were classified as available-for-sale securities for which an accumulated other comprehensive loss of $123,000 and $96,000 were recorded, respectively Net Loss per Share of Common Stock —Basic net loss per share is calculated by dividing the net loss by the weighted-average number of common shares outstanding during the period, without consideration for potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss by the weighted-average number of common shares and potentially dilutive securities outstanding for the period determined using the treasury-stock and if-converted methods. For purposes of the diluted net loss per share calculation, stock warrants, restricted stock units and stock options are considered to be potentially dilutive securities. Because the Company has reported a net loss for all periods presented, diluted net loss per common share is the same as basic net loss per common share for those periods. Recent Accounting Pronouncements — In August 2018, the FASB issued ASU 2018-15, Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract. It clarifies the accounting for implementation costs in cloud computing arrangements. The new guidance requires companies to recognize the implementation costs as expense over the noncancelable term of the cloud computing arrangement plus any optional renewal periods (1) that are reasonably certain to be exercised by the customer or (2) for which exercise of the renewal option is controlled by the cloud service provider. The guidance is effective for fiscal year beginning after December 15, 2019. Early adoption is permitted. Management is currently evaluating early adopting this guidance in 2019 and does not anticipate the impact of this new standard on our consolidated financial statements will be significant. In February 2018, the FASB released ASU 2018-2, “ Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) Adopted In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606) related to the recognition and reporting of revenue that establishes a comprehensive new revenue recognition model designed to depict the transfer of goods or services to a customer in an amount that reflects the consideration the entity expects to receive in exchange for those goods or services. The guidance allows for the use of either the full or modified retrospective transition method. This new standard was effective on January 1, 2018. The Company used the modified retrospective method. Under the new standards, there was no significant impact for revenue to the Company’s end customers and their manufacturing subcontractors; however, the timing for distributor transactions was changed. Under the new standard, the Company recognizes revenues on sales to distributors upon shipment and transfer of control (known as “sell-in” revenue recognition), rather than deferring recognition until distributor report that they have sold the product to their customers (known as “sell-through” revenue recognition). This change in methodology causes a shift in the timing of when revenue is recognized for this class of customers. Deferred revenue of $0.1 million was recorded to retained earnings upon adoption of this new standard on the Company’s consolidated financial statements. In May 2017, the Financial Accounting Standards Board (“FASB”) issued ASU 2017-09, Compensation-Stock Compensation (Topic 718): Scope of Modification Accounting. Topic 718, Compensation-Stock Compensation

Balance Sheet Components

Balance Sheet Components	12 Months Ended
	Dec. 31, 2018
Balance Sheets Components [Abstract]
Balance Sheet Components	3. Balance Sheet Components Inventories consisted of the following (in thousands): December 31, 2018 2017 Processed wafers $ 1,233 $ 3,523 Work in process 5,990 10,118 Finished goods 7,251 4,828 Total inventories $ 14,474 $ 18,469 Prepaid expenses and other current assets consisted of the following (in thousands): December 31, 2018 2017 Processed wafer prepayments $ 67 $ 3,443 Electronic design automation tools 444 519 Other prepaid and other current assets 1,507 1,661 Total other prepaid and other current assets $ 2,018 $ 5,623 Property and equipment, net consisted of the following (in thousands): December 31, Estimated Useful Lives 2018 2017 Machinery and equipment 2-3 years $ 15,237 $ 13,268 Production masks 4 years 5,401 5,401 Software and computer equipment 3 years 4,492 3,820 Leasehold improvements Shorter of estimated life of asset or remaining lease term 1,414 539 Office furniture and fixtures 3 years 117 114 Total property and equipment 26,661 23,142 Less: accumulated depreciation and amortization (17,436 ) (13,169 ) Property and equipment, net $ 9,225 $ 9,973 Depreciation and amortization of property and equipment totaled $5.0 million, $3.9 million and $2.7 million for the years ended December 31, 2018, 2017 and 2016, respectively. Intangible assets, net are carried at cost, less accumulated amortization. Intangible assets were as follows (in thousands): December 31, Estimated Useful Lives 2018 2017 IP license 7 years $ 5,416 $ 5,416 Patents 10-12 years 348 348 Total intangible assets 5,764 5,764 Less: accumulated amortization (2,016 ) (1,208 ) Intangible assets, net $ 3,748 $ 4,556 Amortization of intangible assets totaled $0.8 million, $0.8 million and $0.3 million for the years ended December 31, 2018, 2017 and 2016, respectively. Amortization expense related to amortizable intangibles in future periods as of December 31, 2018 is expected to be as follows (in thousands): 2019 808 2020 808 2021 808 2022 800 2023 and thereafter 524 Total $ 3,748 Accrued liabilities consisted of the following (in thousands): December 31, 2018 2017 Accrued compensation and related benefits $ 5,301 $ 5,242 Customer deposit 40 1,154 Accrued IP license fees 4,829 343 Accrued technical consulting and professional services 412 259 Accrued royalty, rebates, and commission 443 287 Other accrued liabilities 2,882 1,932 Total accrued liabilities $ 13,907 $ 9,217

Financial Instruments

Financial Instruments	12 Months Ended
	Dec. 31, 2018
Investments All Other Investments [Abstract]
Financial Instruments	4. Financial Instruments The following is a summary of financial instruments (in thousands): As of December 31, 2018 Gross Gross Unrealized Unrealized Estimated Fair Cost Gains Losses Values Available-for sale securities Commercial paper $ 10,173 $ - $ (9 ) $ 10,164 Money market funds 403 - - 403 Corporate bonds 52,448 - (114 ) 52,334 U.S. government securities 1,972 - - 1,972 Total available-for-sale securities $ 64,996 $ - $ (123 ) $ 64,873 Reported in: Cash and cash equivalents $ 4,143 Short-term investments 60,730 Total available-for-sale securities $ 64,873 As of December 31, 2017 Gross Gross Unrealized Unrealized Estimated Fair Cost Gains Losses Values Available-for sale securities Commercial paper $ 13,927 $ - $ (11 ) $ 13,916 Money market funds 1,269 - - 1,269 Corporate bonds 36,534 - (81 ) 36,453 U.S. government securities 2,489 - (4 ) 2,485 Total available-for-sale securities $ 54,219 $ - $ (96 ) $ 54,123 Reported in: Cash and cash equivalents $ 5,761 Short-term investments 48,362 Total available-for-sale securities $ 54,123 The contractual maturities of available-for-sale securities are presented in the following table (in thousands): December 31, 2018 Amortized Cost Basis Estimated Fair Value Due in one year or less $ 60,434 $ 60,313 Due between one and five years 4,562 4,560 $ 64,996 $ 64,873 Gross realized gains and gross realized losses on sales of available-for-sale securities for the years ended December 31, 2018 and 2017 were not significant.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	5. Fair Value Measurements The Company defines fair value as the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining the fair value measurements for assets and liabilities which are required to be recorded at fair value, the Company considers the principal or most advantageous market in which to transact and the market-based risk. The Company applies fair value accounting for all financial assets and liabilities that are recognized or disclosed at fair value in the financial statements on a recurring basis. The Company categorizes assets and liabilities recorded at fair value based upon the level of judgment associated with inputs used to measure their fair value. The categories are as follows: Level 1 —Observable inputs, such as quoted prices in active markets for identical, unrestricted assets, or liabilities. Level 2 —Quoted prices for similar assets or liabilities, or inputs other than quoted prices in active markets that are observable either directly or indirectly. Level 3 —Unobservable inputs in which there is little or no market data, which require the Company to develop its own assumptions about the assumptions market participants would use in pricing the asset or liability. Valuation techniques include use of option-pricing models, discounted cash flows models, and similar techniques. The hierarchy requires the Company to use observable market data, when available, and to minimize the use of unobservable inputs when determining fair value. The following tables represent the Company’s financial assets measured at fair value on a recurring basis categorized by the fair value hierarchy as of December 31, 2018 and 2017 (in thousands): As of December 31, 2018 Level 1 Level 2 Level 3 Total Financial asset— available-for-sales securities Money market funds $ 403 $ - $ - $ 403 Commercial paper - 10,164 - 10,164 Corporate bonds - 52,334 - 52,334 U.S. government securities - 1,972 - 1,972 Total financial asset—available-for-sales securities $ 403 $ 64,470 $ - $ 64,873 As of December 31, 2017 Level 1 Level 2 Level 3 Total Financial asset— available-for-sales securities Money market funds $ 1,269 $ - $ - $ 1,269 Commercial paper - 13,916 - 13,916 Corporate bonds - 36,453 - 36,453 U.S. government securities - 2,485 - 2,485 Total financial asset—available-for-sales securities $ 1,269 $ 52,854 $ - $ 54,123 Prior to the repayment of debt and conversion of convertible preferred warrants to common stock warrants in 2017, the summary of changes in the fair value of the Company’s Level 3 financial liabilities was as follows (in thousands): Balance as of December 31, 2016 $ 12,885 Change in fair value of convertible preferred stock warrant liability 990 Exercise of Series H convertible preferred stock warrants (10,738 ) Conversion of convertible preferred stock warrants to common stock warrants upon IPO (3,137 ) Balance as of December 31, 2017 $ - Common Stock Warrants —As of December 31, 2018, the Company has the following outstanding common stock warrants, which were converted from convertible preferred stock warrants upon the closing of the IPO in November 2017 (in thousands except per share data): As of December 31, 2018 Exercise Price Common Shares Converted from Per Share Expiration Date Underlying Warrants Series G $ 14.314298 12/16/2024 64,012 Series G/H $ 14.314298 1/30/2025 19,683 Total Common Stock Warrants 83,695 Below is the description of the previously outstanding convertible preferred stock warrants: Series A Convertible Preferred Stock Warrants Issued to Pinnacle Ventures —As consideration for a 2006 Loan and Security Agreement, the Company issued fully vested warrants to Pinnacle Ventures to purchase 33,499 shares of Series A convertible preferred stock at an exercise price of $8.209000 per share which were fully exercised as of December 31, 2016. Series B Convertible Preferred Stock Warrants Issued to Pinnacle Ventures —As consideration for a 2008 Amended and Restated Loan and Security Agreement with Pinnacle Ventures, the Company issued fully vested warrants to purchase 15,753 shares of Series B convertible preferred stock at an exercise price of $21.502753 per share. These Series B warrants have a term of 10 years. In connection with the issuance of the Series D convertible preferred stock in November 2009, warrants to purchase 12,556 shares of Series B convertible preferred stock automatically converted into warrants to purchase 40,516 shares of Series D convertible preferred stock at $6.663973 per share. This warrant expired in 2018. Series C-1 Convertible Preferred Stock Warrants Issued to Intel Corporation —In connection with entering into an agreement with a customer, the Company issued warrants to purchase up to 400,608 shares of Series C-1 convertible preferred stock at an exercise price of $0.10 per share. The warrants are valued as they vest and become exercisable upon the achievement of certain milestones, primarily related to product development. As of December 31, 2017, warrants to purchase 53,400 shares of Series C-1 convertible preferred stock are subject to potential vesting under the Intel Agreement. The fair value at vesting will be allocated to the Intel Agreement. During the year ended December 31, 2009, warrants to purchase 347,208 shares vested with an initial value of $1,927,505. Prior to 2014, 100,000 of the shares underlying the vested warrants were issued upon exercise of such warrants. The remaining warrants were exercised in 2018. Series D Convertible Preferred Stock Warrants Issued to Pinnacle Ventures —As consideration for a 2009 Amendment to the 2008 Amended and Restated Loan and Security Agreement with Pinnacle Ventures, the Company issued to Pinnacle Ventures fully vested warrants to purchase 21,008 shares of Series D convertible preferred stock. The Company also issued fully vested warrants to purchase an additional 21,008 shares of Series D convertible preferred stock when the Company borrowed an additional $3.5 million in December 2010. In addition, in connection with the issuance of the Series D convertible preferred stock in November 2009, warrants to purchase 12,556 shares of Series B convertible preferred stock automatically converted into fully vested warrants to purchase 40,516 shares of Series D convertible preferred stock. The Series D warrants have an exercise price of $6.663973 per share and a term of ten years and were exercised in 2018. Series F Convertible Preferred Stock Warrants Issued to Pinnacle Ventures —On April 5, 2013, in connection with the 2013 Agreement, the Company issued to Pinnacle Ventures fully vested warrants to purchase 64,655 Series F convertible preferred stock at an exercise price of $9.280000 price per share. These warrants will expire in April 2023 and were exercised in 2018. Series G Convertible Preferred Stock Warrants Issued to Pinnacle Ventures —On December 16, 2014, in connection with the 2013 Amended Agreement, the Company issued to Pinnacle Ventures fully vested warrants to purchase 64,012 shares of Series G convertible preferred stock at an exercise price of $14.314298 per share. At issuance, the estimated fair value was determined using the Monte Carlo Simulation with an aggregate fair value of $173,091 that was determined using the following assumptions: risk-free rate of 2.13%, contractual term of 9.71 years, and volatility of 50%. The warrants will expire in December 2024. Series G or Series H Convertible Preferred Stock Warrants Issued to Hercules Technology Growth Capital —On January 30, 2015, the Company entered into a Loan and Security Agreement with Hercules Technology Growth Capital for an $11.5 million, revolving line of credit. In connection with this agreement, the Company issued fully vested warrants to purchase 19,683 shares at an exercise price of $14.314298 per share. At the election of the holder, these warrants may be exercised for Series G or Series H convertible preferred stock. At issuance, the estimated fair value was determined using the Monte Carlo Simulation with an aggregate fair value of $50,000 that was determined using the following assumptions: risk-free rate of 2.06%, contractual term of 9.83 years, and volatility of 50%. The warrants will expire in January 2025. Series H Convertible Preferred Stock Warrants Issued to GLOBALFOUNDRIES —In connection with the collaboration and development agreement with GLOBALFOUNDRIES on March 25, 2015, the Company issued to GLOBALFOUNDRIES fully vested warrants to purchase 975,616 shares of Series H convertible preferred stock at an exercise price of $0.10 per share. At issuance, the estimated fair value was determined using the Monte Carlo Simulation with an aggregate estimated fair value of $12.0 million that was determined using the following assumptions: risk-free interest rate of 1.03%, expected term of one year, no expected dividends, and volatility of 35%. The fair value of these warrants was recorded as an operating expense in the consolidated statement of operations at the date of issuance. These warrants would have expired at the earlier of March 2025, the Company’s IPO, or a deemed liquidation event. These warrants were exercised in May 2017. The Company recorded a loss of $1.0 million and $0.5 million Determining Fair Value of Convertible Preferred Stock Warrants The assumptions used to determine the fair value of convertible preferred stock warrants relate to the weighted average assumptions from January 1, 2017 through November 3, 2017, when the convertible preferred stock warrants were converted into common stock warrants and for the year ended December 31, 2016 were as follows: Period from January 1, 2017 through November 3, 2017 Year ended December 31, 2016 Valuation method Black-Scholes Pricing Model Black-Scholes Pricing Model Risk-free interest rate 0.89%-2.24% 0.39%-2.25% Expected term 0.4 - 7.9 yrs 0.3 - 9.0 yrs Expected dividends 0% 0% Volatility 25% - 35% 25% - 50% Fair value of preferred stock: Convertible preferred Series A $ 9.00 $ 4.40 Convertible preferred Series B 9.00 7.30 Convertible preferred Series C-1 9.00 7.30 Convertible preferred Series D 9.00 7.80 Convertible preferred Series E 9.00 7.70 Convertible preferred Series F 9.00 9.10 Convertible preferred Series G 9.00 14.00 Convertible preferred Series H 9.00 14.30 There were no transfers within the hierarchy during the years ended December 31, 2018 and 2017.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2018
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	6. Commitments and Contingencies Lease and purchase obligations The Company leases office and research facilities under operating leases for its U.S. headquarters and international locations that expires at various dates through March 2024. Under the lease agreements that contain escalating rent provisions, lease expense is recorded on a straight-line basis over the lease term. Rent expense for the years ended December 31, 2018, 2017 and 2016 was $1.9 million, $1.2 million and $0.9 million, respectively. In addition, the Company has purchase obligations which included agreements and issued purchase orders containing non-cancelable payment terms to purchase goods and services. As of December 31, 2018, future minimum operating lease payments and purchase obligations are as follows (in thousands): Total Operating Purchase Lease and Purchase Leases Obligations Obligations 2019 $ 1,482 $ 15,674 $ 17,156 2020 1,516 4,247 5,763 2021 1,993 1,008 3,001 2022 2,033 - 2,033 2023 and thereafter 2,217 - 2,217 Total $ 9,241 $ 20,929 $ 30,170 Litigation— The Company accrues for contingencies when it believes that a loss is probable and that it can reasonably estimate the amount of any such loss and the Company has made an assessment of the probability of incurring any such losses and whether or not those losses are estimable. Although the Company is not currently subject to any litigation, and no litigation is currently threatened against the Company, the Company may be subject to legal proceedings, claims and litigation, including intellectual property litigation, arising in the ordinary course of business. Such matters are subject to many uncertainties and outcomes and are not predictable with assurance. The Company accrues amounts that it believes are adequate to address any liabilities related to legal proceedings and other loss contingencies that it believes will result in a probable loss that is reasonably estimable. To the extent there is a reasonable possibility that a loss exceeding amounts already recognized may be incurred and the amount of such additional loss would be material, the company will either disclose the estimated additional loss or state that such an estimate cannot be made. The Company does not currently believe that it is reasonably possible that losses in connection with litigation arising in the ordinary course of business would be material. Indemnification— Under the indemnification provisions of the Company’s standard sales related contracts, the Company agrees to defend its customers against third-party claims asserting infringement of certain intellectual property rights, which may include patents, copyrights, trademarks, or trade secrets and to pay judgments entered on such claims. Certain agreements include indemnification provisions that could potentially expose the Company to losses in excess of the amount received under the agreement. In addition, the Company indemnifies its directors and certain of its officers while they are serving in good faith in such capacities. To date, the Company has not incurred costs to defend lawsuits or settle claims related to these indemnification agreements

Common Stock and Share-based Co

Common Stock and Share-based Compensation	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Common Stock and Share-based Compensation	7. Common Stock and Share-based Compensation The Company’s certificate of incorporation, as of December 31, 2018 and 2017, authorized the Company to issue up to 95,000,000 and 400,000,000 shares of common stock, respectively, and 5,000,000 and 10,000,000 shares of preferred stock, each at $0.00001 par value per share, respectively. As of December 31, 2018, no preferred stock was outstanding. Each share of common stock is entitled to one vote. The holders of common stock are also entitled to receive dividends out of funds legally available. No dividends have been declared to date. Immediately prior to the closing of the Company’s IPO, all outstanding shares of its convertible preferred stock automatically converted into 20,816,754 shares of common stock. As such, no shares of convertible preferred stock were outstanding as of December 31, 2018 and 2017. 2015 Equity Incentive Plan and 2004 Equity Incentive Plan Under the Company’s 2015 Equity Incentive Plan and 2004 Equity Incentive Plan, shares of common stock were reserved for the issuance of incentive stock options (“ISO”); nonstatutory stock options (“NSO”); or the sales of restricted common stock to employees, officers, directors, and consultants of the Company. The exercise price of an option is determined by the board of directors when the option is granted and may not be less than 85% of the fair market value of the shares on the date of grant, provided that the exercise price of an ISO is not less than 100% of the fair market value of the shares on the date of grant and the exercise price of any option granted to a 10% stockholder is not less than 110% of the fair market value of the shares on the date of grant. ISOs granted under the Plan generally vest 25% after the completion of 12 months of service and the balance in equal monthly installments over the next 36 months of service and expire 10 years from the grant date. NSOs vest as per the specific agreement and expire 10 years from the date of grant. The Plan allows for early exercise of options prior to full vesting as determined by the board of directors and set forth in the stock option agreements governing such options. Exercises of unvested options are subject to repurchase by the Company at not less than the original exercise price upon termination of employment. 2017 Equity Incentive Plan In November 2017, the Company adopted the 2017 Equity Incentive Plan, or 2017 Plan, and all shares reserved for grant under the 2015 Equity Incentive Plan and 2004 Equity Incentive Plan were cancelled. The 2017 Plan had 3,294,919 common shares reserved, plus any shares subject to outstanding stock options or other stock awards that were granted under the 2015 Equity Incentive Plan and 2004 Equity Incentive Plan that were forfeited, terminate, expire or are otherwise not issued. In addition, the shares reserved under the 2017 Plan will automatically increase on the first day of each calendar year until January 1, 2027, by an amount equal to 5% of the total number of shares of the Company’s capital stock outstanding on the last day of the calendar month before the date of the automatic increase, or a lesser number of shares determined by the board of directors prior to the date of such automatic increase. The 2017 Plan provides for the grant of common stock awards, including incentive stock options, non-statutory stock options, stock appreciation rights, restricted stock and restricted stock units, performance units and performance shares to employees, directors, and consultants of the Company. All granted shares that are canceled, forfeited or expired are returned to the 2017 Plan and are available for grant in conjunction with the issuance of new equity awards. Stock options may be granted at an exercise price per share not less than 100% of the fair market value at the date of grant. If a stock option is granted to a 10% stockholder, then the exercise price per share must not be less than 110% of the fair market value per share of common stock on the grant date. Options granted are exercisable over a maximum term of 10 years from the date of grant and generally vest over a period of four years. As of December 31, 2018, 2,367,378 shares are available for grant. Stock options Activity of stock options granted under the Company’s equity incentive plans is set forth below: Weighted- Weighted Average Average Remaining Aggregate Number of Exercise Contractual Intrinsic Value Shares Price Term (Years) (in thousands) Balance—January 1, 2016 4,827,785 $ 2.38 7.2 $ 9,759 Granted 570,939 $ 4.32 Exercised (2,459,180 ) $ 1.85 Canceled (32,948 ) $ 3.11 Balance—December 31, 2016 2,906,596 $ 3.20 8.1 $ 4,941 Granted 1,320,382 $ 7.08 Exercised (388,621 ) $ 3.28 Canceled (104,813 ) $ 4.53 Balance—December 31, 2017 3,733,544 $ 4.53 7.9 $ 25,386 Granted 1,000 $ 13.89 Exercised (825,150 ) $ 3.38 Canceled (611,991 ) $ 6.23 Balance—December 31, 2018 2,297,403 $ 4.49 6.9 $ 9,858 Vested and exercisable—December 31, 2018 1,547,754 $ 3.74 6.5 $ 7,803 Vested and exercisable—December 31, 2017 1,648,917 $ 2.89 6.7 $ 13,924 Outstanding options and exercisable options information by range of exercise prices as of December 31, 2018 was as follows: Outstanding Options Exercisable Options Weighted Average Remaining Weighted Weighted Range of Number of Contractual Term Average Number of Average Exercise Prices Shares (in Years) Exercise Price Shares Exercise Price $ 1.10 to $ 1.90 52,200 1.8 $ 1.50 52,200 $ 1.50 $ 2.00 to $ 3.90 961,800 6.0 $ 2.78 961,800 $ 2.78 $ 4.30 to $ 7.10 1,234,953 7.8 $ 5.76 1,167,626 $ 5.84 $ 8.61 to $ 9.90 47,450 8.7 $ 9.33 33,012 $ 9.65 $ 9.91 to $ 13.89 1,000 9.3 $ 13.89 1,000 $ 13.89 Total 2,297,403 6.9 $ 4.49 2,215,638 $ 4.47 As of December 31, 2018, approximately $2.0 million of unrecognized stock compensation costs related to awards were expected to be recognized over a weighted-average period of 2.8 years. As of December 31, 2017, approximately $4.8 million of unrecognized stock compensation costs related to awards were expected to be recognized over a weighted-average period of 3.1 years. The aggregate intrinsic value of options exercised for the year ended December 31, 2018 was $7.1 million. The aggregate intrinsic value of options exercised during the year ended December 31, 2017 was $1.6 million. The weighted-average grant-date fair value of options granted for the year ended December 31, 2018, was $5.46 per share. The weighted-average grant-date fair value of options granted during the year ended December 31, 2017 was $2.94 per share. The calculated fair value of option grants was estimated using the Black-Scholes model with the following assumptions for which options were granted: Year ended December 31, 2018 2017 2016 Risk-free interest rate 2.87 % 1.89%-2.40% 1.46%-2.43% Expected term 6.1 yrs 6.1 - 10 yrs 6.1 - 10 yrs Expected dividends 0 % 0 % 0 % Volatility 35 % 26% - 30% 30% - 34% Employee Stock Purchase Plan Concurrent with the completion of the IPO in November 2017, the Company adopted the 2017 Employee Stock Purchase Plan, or ESPP. The ESPP authorizes the issuance of 1,317,967 shares of common stock outstanding under purchase rights granted to its employees. In addition, the shares reserved under the ESPP Plan will automatically increase on the first day of each calendar year until January 1, 2027, by the lesser of (i) an amount equal to 2% of the total number of shares of the Company’s capital stock outstanding on the last day of the calendar month before the date of the automatic increase, (ii) 1,000,000 shares of common stock, and (iii) a lesser number of shares determined by the board of directors prior to the date of such automatic increase. The ESPP allows eligible employees to purchase shares of the Company’s common stock at a discount through payroll deductions of up to 15% of their eligible compensation, subject to any plan limitations. The ESPP generally provides for offering periods and purchase periods every six months, and at the end of each purchase period, employees are able to purchase shares at 85% of the lower of the fair market value of the Company’s common stock on the first trading day of the purchase period or on the last trading day of the offering period. 366,369 shares were issued as of December 31, 2018 under the ESPP. Shares expected to be issued under the ESPP were 203,986 for the offering period as of December 31, 2018. The calculated fair value of the shares under the ESPP was estimated using the Black-Scholes model with the following assumptions: risk-free interest rate in the range of 1.31% and 2.36%, expected term of 0.5 year, expected dividends of 0% and volatility of 22%. For the year ended December 31, 2018 and 2017, unamortized compensation expense related to the ESPP was approximately $0.5 million and $0.5 million, respectively, to be recognized over approximately five months at each year end. Restricted Stock Unit Awards The Company grants restricted stock units (RSU) to employees under the 2017 Plan. RSUs granted typically vest ratably over a four-year period, and are converted into shares of the Company’s common stock upon vesting on a one-for-one basis subject to the employee’s continued service to the Company over that period. The fair value of RSUs is determined using the fair value of the Company’s common stock on the date of the grant, reduced by the discounted present value of dividends expected to be declared before the awards vest. Compensation expense is recognized on a straight-line basis over the requisite service period of each grant. Each RSU award granted from the 2017 Plan will reduce the number of shares available for issuance under the 2017 Plan by one share. As of December 31, 2018, and 2017, unamortized compensation expense related to RSU was approximately $15.8 million and $0.4 million, to be recognized over 3.0 years and 1.8 years, respectively. Activity of RSU granted under the Company’s equity incentive plans is set forth below: Weighted Average Market Number of Units Value Balance—January 1, 2017 - $ - Granted 35,029 $ 10.56 Released - $ - Canceled - $ - Balance—December 31, 2017 35,029 $ 10.56 Granted 1,657,237 $ 12.76 Released (24,929 ) $ 11.53 Canceled (113,248 ) $ 13.01 Balance—December 31, 2018 1,554,089 $ 12.73 The Company uses the straight-line vesting attribution method to record stock-based compensation expense. Stock-based compensation expense recognized in the consolidated statements of operations and comprehensive loss was as follows (in thousands): Year ended December 31, 2018 2017 2016 Cost of revenue $ 156 $ 47 $ 31 Research and development 3,793 973 489 Sales and marketing 843 197 95 General and administrative 1,728 456 324 Total $ 6,520 $ 1,673 $ 939 No income tax benefit associated with stock-based compensation expense was recognized in the consolidated statements of operations and comprehensive income (loss) for the years ended December 31, 2018, 2017 and 2016.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	8. Income Taxes The following table represents domestic and foreign components of income (loss) before income taxes for the periods presented (in thousands): Year Ended December 31, 2018 2017 2016 Domestic $ (5,475 ) $ 4,195 $ (992 ) Foreign (3,822 ) (9,729 ) 715 Total $ (9,297 ) $ (5,534 ) $ (277 ) The Company’s provision for (benefit from) income taxes was as follows (in thousands): Year Ended December 31, 2018 2017 2016 Current: Federal $ - $ - $ (63 ) State 1 1 1 Foreign 474 (118 ) 230 Total current: 475 (117 ) 168 Deferred: Federal - - - State - - - Foreign - - - Total deferred benefit: - - - Total provision for (benefit from) income taxes $ 475 $ (117 ) $ 168 Reconciliation of the statutory federal income tax rate to the Company’s effective income tax rate is as follows: Year Ended December 31, 2018 2017 2016 Federal tax at statutory rate 21 % 34 % 34 % Foreign taxes (14 ) (58 ) 5 State taxes 7 (2 ) 316 Change in warrant valuation - (6 ) (66 ) Stock-based compensation 1 (5 ) (80 ) Research and development credit 22 14 343 Changes in reserves for uncertain tax positions (18 ) 3 (731 ) Change in valuation allowance (17 ) 283 114 2017 Tax Cut and Jobs Act impact - (283 ) - Tax effect upon adoption of ASU 2016-09 - 19 - GILTI inclusion (3 ) - - Other (4 ) 3 4 Total (5 ) % 2 % (61 ) % Significant components of the Company’s net deferred tax assets were as follows (in thousands): Year Ended December 31, 2018 2017 Deferred tax assets: Net operating loss carryforwards $ 29,311 $ 31,286 Tax credit carryforwards 12,376 9,439 Accruals recognized in different periods 1,041 1,115 Fixed assets depreciation 381 137 Stock-based compensation 734 113 Other 96 22 Gross deferred tax assets: 43,939 42,112 Deferred tax liabilities: Other (135 ) (81 ) Subtotal 43,804 42,031 Valuation allowance (43,804 ) (42,031 ) Total net deferred tax assets $ - $ - Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income (or loss) in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized as income tax expense (benefit) in the period that includes the enactment date. Valuation allowances are established when it is more likely than not that some portion of the deferred tax assets will not be realized. On December 22, 2017, the U.S. government enacted comprehensive tax legislation commonly referred to as the Tax Cuts and Jobs Act (the “Act”). The Act made broad and complex changes to the U.S. tax code including, but not limited to: (1) reducing the U.S. federal corporate tax rate from 35 percent to 21 percent; (2) requiring companies to pay a one-time transition tax on certain unrepatriated earnings of foreign subsidiaries; (3) generally eliminating U.S. federal income taxes on dividends from foreign subsidiaries; (4) requiring current inclusion in U.S. federal taxable income of certain earnings of controlled foreign corporations; (5) eliminating the corporate alternative minimum tax, or AMT, and changing how existing AMT credits can be realized; (6) creating the base erosion anti-abuse tax, or BEAT, a new minimum tax; (7) creating a new limitation on deductible interest expense; and (8) changing rules related to uses and limitations of net operating loss carryforwards created in tax years beginning after December 31, 2017. Under the new corporate income tax rate of 21%, U.S. federal and state deferred tax assets decreased by approximately $15.7 million and the valuation allowance decreased by approximately the same amount as of December 31, 2017 when the Act was enacted. Due to the valuation allowance on the deferred tax assets, the provisional amount recorded related to the remeasurement was zero. As of December 31, 2017, the Company's foreign subsidiaries are in a cumulative deficit. Therefore, the one-time transition tax on deemed repatriation of previously untaxed accumulated earnings and profits of foreign subsidiaries had minimal impact on the Company. Undistributed earnings of foreign subsidiaries are determined to be reinvested indefinitely. Therefore, there was no accounting impact resulted from this provision of the Act. The SEC staff issued Staff Accountant Bulletin No. 118, or SAB 118, which provides guidance on accounting for the tax effects of the Act. SAB 118 provides a measurement period that should not extend beyond one year from the Act enactment date for companies to complete the accounting under ASC 740. In accordance with SAB 118, a company must reflect the income tax effects of those aspects of the Act for which the accounting under ASC 740 is complete. To the extent that a company’s accounting for certain income tax effects of the Act is incomplete but it is able to determine a reasonable estimate, it must record a provisional estimate in the financial statements. If a company cannot determine a provisional estimate to be included in the financial statements, it should continue to apply ASC 740 on the basis of the provisions of the tax laws that were in effect immediately before the enactment of the Act. At December 31, 2018, the Company completed its analysis on the Act including (a) provisions for Global Intangible Low-Taxed Income, or GILTI, wherein taxes on foreign income are imposed in excess of a deemed return on tangible assets of foreign corporations and elected the accounting policy to record the tax provision related to GILTI using the period expense method and (b) state tax implications of the Act resulting in no adjustment to the consolidated financial statements. The Company will continue to monitor changes in tax regulations and guidance as it relates to the Act, which may cause us to record further adjustments to the consolidated financial statements. Based on the available objective evidence, both positive and negative, management believes that it is more likely than not that the net deferred tax assets will not be realized. Accordingly, the Company has provided a full valuation allowance against net deferred tax assets as of December 31, 2018, 2017 and 2016. The valuation allowance for deferred tax assets was $43.8 million, $42.0 million and $58.5 million as of December 31, 2018, 2017 and 2016, respectively. The change in the valuation allowance for the years ended December 31, 2018, 2017 and 2016 was $1.8 million, $(16.5) million and $(3.2) million, respectively. As of December 31, 2018, the Company had net operating loss, or NOL, carryforwards of approximately $175.7 million and $92.0 million for federal and state income tax purposes, respectively. The NOL carryforwards begin to expire in 2025 and 2019 for federal and state purposes, respectively. As of December 31, 2018, the Company had research and development tax credit carryforwards of approximately $8.9 million and $9.6 million for federal and state income tax purposes, respectively. The federal tax credit carryforwards begin to expire in 2026 and the state tax credits carry forward indefinitely. Internal Revenue Code Section 382 and similar California rules place a limitation on the amount of taxable income that can be offset by NOL carryforwards after a change in control (generally greater than 50% change in ownership). Generally, after a control change, a corporation cannot deduct NOL carryforwards in excess of the Section 382 limitations. Due to these provisions, utilization of NOL and tax credit carryforwards may be subject to annual limitations regarding their utilization against taxable income in future periods. The Company completed Section 382 analysis in 2016 and determined ownership changes occurred in July 2005, November 2009 and August 2017, which resulted in reductions to the U.S. federal and California net operating losses of $34.9 million and $24.1 million, respectively, and U.S. federal research and development credits by $1.8 million. Reconciliation of the beginning and ending balances of the gross unrecognized tax benefits during the years ended December 31, 2018, 2017 and 2016 were as follows (in thousands): Year Ended December 31, 2018 2017 2016 Unrecognized benefits - beginning of period $ 7,047 $ 4,323 $ 4,100 Increases in balances related to tax positions taken during a prior period 1,783 2,567 - Increases in balances related to tax positions taken during the current period - 1,276 224 Decreases in balances related to tax positions taken during a prior period (58 ) (1,119 ) (1 ) Unrecognized benefits - end of period $ 8,772 $ 7,047 $ 4,323 The Company’s policies are to record the tax provision related to GILTI using the period expense method and to classify interest and penalties associated with unrecognized tax benefits as income tax expense. The Company had no interest or penalty accruals associated with uncertain tax benefits in its balance sheets and statements of operations and comprehensive loss for the years ended December 31, 2018, 2017 and 2016. Although the Company files U.S. federal and various state tax returns, the Company’s only major tax jurisdictions are the United States and California. As a result of NOL carryforwards, all of the Company’s tax years are open to federal and state examination in the United States. All tax years are open to examination in various foreign countries.

Net Loss Per Share

Net Loss Per Share	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Net Loss Per Share	9. Net Loss Per Share The following table summarizes the computation of basic and diluted net loss per share (in thousands, except share and per share data): Year Ended December 31, 2018 2017 2016 Net loss $ (9,772 ) $ (5,417 ) $ (445 ) Weighted-average common shares outstanding 34,181,200 9,204,384 4,240,461 Less: Shares subject to repurchase - - - Weighted-average shares outstanding 34,181,200 9,204,384 4,240,461 Net loss per share, basic and diluted $ (0.29 ) $ (0.59 ) $ (0.10 ) Basic net loss per share is computed by dividing the net loss by the weighted-average number of common shares outstanding for the period. Basic and diluted net loss per share is presented in conformity with the two-class method required for participating securities. Prior to the IPO, the holders of the Company’s convertible preferred stock were entitled to receive non-cumulative dividends, payable prior and in preference to any dividends on shares of the common stock. Any additional dividends would be distributed among the holders of convertible preferred stock and common stock pro rata, assuming the conversion of all convertible preferred stock into common stock. After to the IPO, all convertible preferred stocks were converted to common stock and the Company has one class of stock issued and outstanding. Because the Company has reported a net loss for the years ended December 31, 2018, 2017 and 2016, diluted net loss per common share is the same as basic net loss per common share for those periods. The following potentially dilutive securities outstanding have been excluded from the computation of diluted weighted-average shares outstanding because such securities have an antidilutive impact due to losses reported (in common stock equivalent shares): As of December 31, 2018 2017 2016 Stock options to purchase common stock 2,297,403 3,733,544 2,831,850 Unvested restricted stock units 1,554,089 35,029 - Convertible preferred stock - - 19,833,843 Common stock warrants 83,695 584,148 1,559,764 Total 3,935,187 4,352,721 24,225,457

Segment Reporting

Segment Reporting	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Segment Reporting	10. Segment Reporting The Company operates in one reportable segment related to the design, development and sale of network communication integrated circuits. The Company’s chief operating decision-maker (“CODM”) is its Chief Executive Officer, who reviews operating results on an aggregate basis and manages the Company’s operations as a whole for the purpose of evaluating financial performance and allocating resources. Substantially all of the Company’s long-lived assets were attributable to operations in the United States as of December 31, 2018, 2017 and 2016. The following table summarizes revenue by market (in thousands): Year Ended December 31, 2018 2017 2016 Revenue by market: Data Center $ 63,549 $ 64,781 $ 64,024 Enterprise Infrastructure 42,482 35,208 22,476 Access 14,094 3,132 175 Automotive 659 250 - Total revenue $ 120,784 $ 103,371 $ 86,675 The Company sells its products worldwide and attributes revenue to the geography where the product is shipped. The geographical distribution of revenue as a percentage of total revenue for the periods indicated was as follows: Year Ended December 31, 2018 2017 2016 Malaysia 58 % 61 % 69 % China 26 30 26 United States 2 1 1 Other 14 8 4 Total 100 % 100 % 100 %

Concentrations

Concentrations	12 Months Ended
	Dec. 31, 2018
Risks And Uncertainties [Abstract]
Concentrations	11. Concentrations Credit —Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash and cash equivalents and accounts receivable. The Company’s cash equivalents consist of checking and money market accounts with a financial institution that management believes to be of high-credit quality; however, at times, balances exceed federally insured limits. Amounts held on deposit at financial institutions in excess of Federal Deposit Insurance Corporation-insured amounts were $1.1 million, $0.9 million and $28.0 million at December 31, 2018, 2017 and 2016, respectively. Significant Customers —Credit risk with respect to accounts receivable is concentrated with two large customers that contribute a majority of the Company’s business and is mitigated by a relatively short collection period. Collateral is not required for accounts receivable. The fair value of accounts receivable approximates their carrying value. Revenue and accounts receivables concentrated with significant customers and their manufacturing subcontractors, as a percentage of total revenue and accounts receivable was as follows: As of December 31, 2018 2017 Accounts Receivable: Customer A 42 % 49 % Customer B 19 34 Year Ended December 31, 2018 2017 2016 Revenue: Customer A 49 % 60 % 68 % Customer B 27 28 21 Significant Suppliers — The Company depends on a limited number of subcontractors and suppliers for its wafer and substrate supply and to fabricate, assemble, and test its semiconductor devices. The Company generally sources its production through standard purchase orders and has wafer supply and assembly and test agreements with certain outside contractors. While the Company seeks to maintain a sufficient level of supply and endeavors to maintain ongoing communications with suppliers to guard against interruptions or cessation of supply, business and results of operations could be adversely affected by a stoppage or delay of supply, substitution of more expensive or less reliable products or services, receipt of defective semiconductor devices, an increase in the price of products, or an inability to obtain reduced pricing from suppliers in response to competitive pressures.

Employee Benefit Plan

Employee Benefit Plan	12 Months Ended
	Dec. 31, 2018
Text Block [Abstract]
Employee Benefit Plan	12. Employee Benefit Plan The Company has established a 401(k) plan, which permits participants to make contributions by salary deduction pursuant to Section 401(k) of the Internal Revenue Code. The Company may, at its discretion, make matching contributions to the 401(k) Plan. The Company has made no contributions to the 401(k) Plan since its inception.

Related Party Transaction

Related Party Transaction	12 Months Ended
	Dec. 31, 2018
Related Party Transactions [Abstract]
Related Party Transaction	13. Related Party Transaction In 2016, the Company entered into an agreement with a significant stockholder to license certain technology intended to be incorporated into the Company’s products under development. Under this agreement, the Company agreed to pay an initial $2.0 million licensing fee and additional licensing fees at a later point of the development program upon the achievement of certain development milestones. In addition, royalties may be due on products sold utilizing the licensed technology. From time to time, the Company also purchases tooling, mask sets, wafers and services from this stockholder in its ordinary course of business. As of December 31, 2017, the total balance due this stockholder was $3.4 million, which was included in accrued, accounts payable and other long-term liabilities. In May 2018, this stockholder ceased to be a beneficial owner of more than 5% of the outstanding common stock.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates —The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the consolidated financial statements, and the reported amounts of expenses during the reporting period. Significant estimates used in the preparation of the consolidated financial statements include revenue recognition, the valuation of deferred tax assets, uncertain tax positions, and useful lives of long-lived assets. These estimates and the underlying assumptions are based on management’s best estimates and judgment. Management evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors and adjusts such estimates and assumptions when facts and circumstances dictate. As future events and their effects cannot be determined with precision, actual results could differ significantly from these estimates.
Financial Instruments	Financial Instruments —Financial instruments held by the Company consist primarily of corporate bonds, U.S. government securities, commercial paper and money market funds. The Company considers all highly liquid financial instruments purchased with an original maturity or remaining maturities of three months or less at the date of purchase to be cash equivalents. All remaining financial instruments are classified as short-term investments. The Company’s financial instruments are classified as available-for-sale. Unrealized gains and losses on securities, net of tax, are recorded in accumulated other comprehensive loss and reported as a separate component of stockholders’ equity. Interest and dividend income and realized gains or losses are included in other income, net on the consolidated statements of operations and comprehensive loss. The Company evaluates the investments periodically for possible other-than-temporary impairment and reviews factors such as the length of time and extent to which fair value has been below cost basis, the financial condition of the issuer, the Company’s intent to hold and whether the Company will not be required to sell the security before its anticipated recovery, on a more-likely-than-not basis. If the declines in the fair value of the investments are determined to be other-than-temporary, the Company reports the credit loss portion of such decline in other income, net and the remaining noncredit loss portion in accumulated other comprehensive loss. The cost of securities sold is based on the specific identification method.
Accounts Receivable	Accounts Receivable —The Company’s receivables are recorded when due and payable. The carrying value of the accounts receivable represents their estimated net realizable value which is reduced by an allowance for doubtful accounts that reflects management’s best estimate of amounts that will not be collected. Based on historical loss experience has been negligible, no allowance for doubtful account has been charged against accounts receivable in the periods presented.
Inventories	Inventories —Inventories consist of processed wafers, work-in-process and finished goods and are stated at the lower of standard cost or net realizable value. Standard costs approximate actual costs and are based on a first-in, first-out basis. The Company performs detailed reviews of the net realizable value of inventories, both on hand as well as for inventories that it is committed to purchase and writes down the inventory value for estimated deterioration, excess and obsolete and other factors based on management’s assessment of future demand and market conditions. Once written down, inventory write downs are not reversed until the inventory is sold or scrapped. For each of the year ended December 31, 2018 and 2017, inventory write-downs were negligible.
Deferred Initial Public Offering Costs	Deferred Initial Public Offering Costs —Deferred initial public offering costs, consisting of direct and incremental legal, accounting and other fees and costs attributable to the Company’s IPO and the preparation of the related registration statement, are capitalized. The total deferred offering costs of $5.7 million were offset against the proceeds received upon the closing of the IPO.
Property and Equipment	Property and Equipment —Property and equipment is initially recorded at cost and depreciated using the straight-line method over the estimated useful lives of the assets. Leasehold improvements are amortized over the estimated useful life or the original lease term, whichever is shorter.
Intangible Assets	Intangible Assets —Intangible assets consist of patents and IP license and are amortized over their useful lives of 7-12 years using a straight-line amortization method.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets —Long-lived assets, such as property and equipment and intangible assets, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to estimated undiscounted future cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated future cash flows, an impairment charge is recognized in the amount by which the carrying amount of the asset exceeds the undiscounted future cash flows. The Company has not recorded any impairment charges in any of the periods presented.
Product Warranty	Product Warranty —The Company’s products are generally sold with a limited standard warranty for a period of one to three years, warranting that the product conforms to specifications and is free from material defects in design, materials and workmanship. To date, the Company has had negligible returns of any defective production parts
Convertible Preferred Stock Warrant Liability	Convertible Preferred Stock Warrant Liability —The Company accounted for its convertible preferred stock warrants outstanding prior to the IPO as derivative liabilities as the terms of the warrants were not fixed due to potential adjustments in the exercise price and the number of shares upon an equity financing at a lower price. The convertible preferred stock warrants were initially recorded at fair value when issued, with gains and losses arising from changes in fair value recognized in other income (expense) in the consolidated statements of operations and comprehensive loss at each period end while such instruments were outstanding and classified as liabilities. The fair values of the convertible preferred stock warrants issued in connection with debt agreements were recorded as debt discounts and were amortized as non-cash interest expense in the consolidated statement of operations over the expected term of the debt agreements. Upon the exercise of the warrants, the liability was reclassified to convertible preferred stock at its then fair value. Upon the completion of the IPO in November 2017, the warrants were converted into warrants to purchase shares of common stock and the liability was reclassified to stockholders’ equity at their then fair value, and was no longer subject to fair value accounting.
Convertible Preferred Stock	Convertible Preferred Stock —Prior to the IPO, the Company recorded convertible preferred stock at fair value on the dates of issuance, net of issuance costs. The convertible preferred stock is recorded outside of stockholders’ equity because the shares contain liquidation features that were not solely within the Company’s control. The Company has elected not to adjust the carrying values of the convertible preferred stock to the liquidation preferences of such shares because it was uncertain whether or when an event would occur that would obligate the Company to pay the liquidation preferences to holders of shares of convertible preferred stock. Subsequent adjustments to the carrying values to the liquidation preferences were made only when it becomes probable that such a liquidation event will occur. In November 2017, all outstanding convertible preferred stock was converted to common stock and the balance of convertible preferred stock was reclassified to additional paid in capital upon the closing of the IPO.
Revenue Recognition	Revenue Recognition — Product revenues consist of sales to customers which are mainly comprised of end customers, their manufacturing subcontractors, and distributors. Revenue is recognized after the Company (a) identifies the contract with a customer, (b) identifies the performance obligations in the contract, (c) determines the transaction price, (d) allocates the transaction price to the performance obligations in the contract, and (e) satisfies the performance obligation when the control of products is transferred to the customer. The Company considers the purchase orders, which in some cases are governed by master sales agreements, to be the contract with its customers. In evaluating the existence of the contract, the Company considers various factors relative to the contract including the customer’s ability to pay amounts due under the contract. The Company is obligated to deliver a fixed number of products to its customers, each of which is distinct, and have been separately identified to be the performance obligations. The Company generally provides an assurance warranty that its products will substantially conform to the published specifications for twelve months from the date of shipment. The Company has not provided services in addition to the standard warranty. As such, the Company does not consider activities related to such warranty, if any, to be a separate performance obligation. In determining the transaction price, the Company considers the variability of the amount due under the contract including amounts subject to refund or adjustment when determining the net consideration to which the Company expects to be entitled within the contract. As the Company’s standard payment terms are less than one year, the Company has elected the practical expedient under the accounting guidance and does not assess whether the contract has a significant financing component. The Company allocates revenue to each product based on their relative standalone selling price. Frequently, the Company receives orders for products to be delivered over multiple dates that may extend across several reporting periods. The Company invoices for each delivery upon shipment and recognizes revenues for each distinct product delivered, assuming transfer of control has occurred. As scheduled delivery dates are within one year, under the optional exemption revenues allocated to future shipments of partially completed contracts are not disclosed. The Company has also elected the practical expedient under ASC 340-40-25-4, “ Other Assets and Deferred Costs”, Sales to certain of end customers include limited rebates. The Company estimates these rebates, using historical volumes of such rebates, at the time revenue is recognized. Such rebates were not significant in any of the periods presented, and the differences between the actual amount of such rebates and our estimates also were not significant. Sales to most of our distributors are made under contracts that allow for pricing credits upon shipment to the end customer and rights of return for on hand inventory at the distributor. Under the accounting guidance, revenue is recognized at the point of transfer of control to the distributor, which typically occurs at the point of shipment. The Company adjusts the transaction price for any unprocessed claims and for future estimated pricing credits which is recorded in accrued liabilities on the consolidated balance sheets. The adjustments for these estimates are recorded as a reduction to revenue in the same period when the related revenue is recorded and is calculated based on an analysis of the historical actual claims received, both in aggregate and at a distributor level to the extent that it is probable that a significant future reversal of revenue will not occur. Historically, adjustments for actual pricing credits and product returns have not been significantly differed from the amounts estimated by the Company. As of December 31, 2018, the Company has recorded an accrued liability of $0.3 million related to the above adjustments to transaction price.
Cost of Revenue	Cost of Revenue —Cost of revenue consists of wafers, processed by third-party foundries, costs associated with packaging, assembly, and test paid to third-party contract manufacturers, and personnel and other costs associated with the Company’s manufacturing operations. Cost of revenue also includes allocation of overhead and facility costs, depreciation of production equipment, inventory write-downs and amortization of production mask costs.
Research and Development	Research and Development —Research and development expenses are charged to operations as incurred. These costs include personnel costs, pre-production engineering mask costs, software license and intellectual property expenses, design tools and prototype-related expenses, facility costs, supplies and depreciation expense. The Company enters into development agreements with some of its customers that provide fees that partially offset development costs. Such fees are recognized upon completion of the contract deliverables or milestones, and acceptance by the customer, if required.
Income Taxes	Income Taxes —Deferred tax assets and liabilities are recognized for the expected future tax consequences of temporary differences between the financial statements’ carrying amounts of existing assets and liabilities and their respective tax basis and net operating loss and tax credit carryforwards. Valuation allowances are established when necessary to reduce deferred tax assets to the amount expected to be realized. A tax position is recognized only if it is more likely than not to be sustained based solely on its technical merits as of the reporting date and then only in an amount more likely than not to be sustained upon review by the tax authorities. The Company considers many factors when evaluating and estimating its tax positions and tax benefits, which may require periodic adjustments and which may not accurately represent actual outcomes.
Stock-Based Compensation	Stock-Based Compensation —Compensation expense related to stock-based transactions is measured and recognized in the financial statements at fair value. Stock-based compensation expense is measured at the grant date based on the fair value of the equity award and is recognized as expense, less actual forfeitures (see Note 7), over the requisite service period, which is generally the vesting period on the straight-line method. The Company estimates the fair value of each stock option award on the date of grant using the Black-Scholes option-pricing model. Determining the fair value of stock option awards at the grant date requires judgment, including estimating the common stock fair value, expected term, expected volatility, risk-free interest rate, and expected dividends. The Company accounts for equity instruments issued to nonemployees based on the fair value of the awards determined using the Black-Scholes option pricing model. The fair value of such instruments is recognized as an expense over the vesting period.
Other Comprehensive Loss	Other Comprehensive Loss —As of December 31, 2018 and 2017, the Company purchased financial instruments which were classified as available-for-sale securities for which an accumulated other comprehensive loss of $123,000 and $96,000 were recorded, respectively
Net Loss per Share of Common Stock	Net Loss per Share of Common Stock —Basic net loss per share is calculated by dividing the net loss by the weighted-average number of common shares outstanding during the period, without consideration for potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss by the weighted-average number of common shares and potentially dilutive securities outstanding for the period determined using the treasury-stock and if-converted methods. For purposes of the diluted net loss per share calculation, stock warrants, restricted stock units and stock options are considered to be potentially dilutive securities. Because the Company has reported a net loss for all periods presented, diluted net loss per common share is the same as basic net loss per common share for those periods.
Recent Accounting Pronouncements	Recent Accounting Pronouncements — In August 2018, the FASB issued ASU 2018-15, Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract. It clarifies the accounting for implementation costs in cloud computing arrangements. The new guidance requires companies to recognize the implementation costs as expense over the noncancelable term of the cloud computing arrangement plus any optional renewal periods (1) that are reasonably certain to be exercised by the customer or (2) for which exercise of the renewal option is controlled by the cloud service provider. The guidance is effective for fiscal year beginning after December 15, 2019. Early adoption is permitted. Management is currently evaluating early adopting this guidance in 2019 and does not anticipate the impact of this new standard on our consolidated financial statements will be significant. In February 2018, the FASB released ASU 2018-2, “ Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) Adopted In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606) related to the recognition and reporting of revenue that establishes a comprehensive new revenue recognition model designed to depict the transfer of goods or services to a customer in an amount that reflects the consideration the entity expects to receive in exchange for those goods or services. The guidance allows for the use of either the full or modified retrospective transition method. This new standard was effective on January 1, 2018. The Company used the modified retrospective method. Under the new standards, there was no significant impact for revenue to the Company’s end customers and their manufacturing subcontractors; however, the timing for distributor transactions was changed. Under the new standard, the Company recognizes revenues on sales to distributors upon shipment and transfer of control (known as “sell-in” revenue recognition), rather than deferring recognition until distributor report that they have sold the product to their customers (known as “sell-through” revenue recognition). This change in methodology causes a shift in the timing of when revenue is recognized for this class of customers. Deferred revenue of $0.1 million was recorded to retained earnings upon adoption of this new standard on the Company’s consolidated financial statements. In May 2017, the Financial Accounting Standards Board (“FASB”) issued ASU 2017-09, Compensation-Stock Compensation (Topic 718): Scope of Modification Accounting. Topic 718, Compensation-Stock Compensation

Balance Sheet Components (Table

Balance Sheet Components (Tables)	12 Months Ended
	Dec. 31, 2018
Balance Sheets Components [Abstract]
Schedule of Inventories	Inventories consisted of the following (in thousands): December 31, 2018 2017 Processed wafers $ 1,233 $ 3,523 Work in process 5,990 10,118 Finished goods 7,251 4,828 Total inventories $ 14,474 $ 18,469
Schedule of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consisted of the following (in thousands): December 31, 2018 2017 Processed wafer prepayments $ 67 $ 3,443 Electronic design automation tools 444 519 Other prepaid and other current assets 1,507 1,661 Total other prepaid and other current assets $ 2,018 $ 5,623
Schedule of Property and Equipment, Net	Property and equipment, net consisted of the following (in thousands): December 31, Estimated Useful Lives 2018 2017 Machinery and equipment 2-3 years $ 15,237 $ 13,268 Production masks 4 years 5,401 5,401 Software and computer equipment 3 years 4,492 3,820 Leasehold improvements Shorter of estimated life of asset or remaining lease term 1,414 539 Office furniture and fixtures 3 years 117 114 Total property and equipment 26,661 23,142 Less: accumulated depreciation and amortization (17,436 ) (13,169 ) Property and equipment, net $ 9,225 $ 9,973
Schedule of Intangible Assets	Intangible assets, net are carried at cost, less accumulated amortization. Intangible assets were as follows (in thousands): December 31, Estimated Useful Lives 2018 2017 IP license 7 years $ 5,416 $ 5,416 Patents 10-12 years 348 348 Total intangible assets 5,764 5,764 Less: accumulated amortization (2,016 ) (1,208 ) Intangible assets, net $ 3,748 $ 4,556
Schedule of Amortization Expense Related to Amortizable Intangibles In Future Periods	Amortization expense related to amortizable intangibles in future periods as of December 31, 2018 is expected to be as follows (in thousands): 2019 808 2020 808 2021 808 2022 800 2023 and thereafter 524 Total $ 3,748
Schedule of Accrued Liabilities	Accrued liabilities consisted of the following (in thousands): December 31, 2018 2017 Accrued compensation and related benefits $ 5,301 $ 5,242 Customer deposit 40 1,154 Accrued IP license fees 4,829 343 Accrued technical consulting and professional services 412 259 Accrued royalty, rebates, and commission 443 287 Other accrued liabilities 2,882 1,932 Total accrued liabilities $ 13,907 $ 9,217

Financial Instruments (Tables)

Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2018
Investments All Other Investments [Abstract]
Summary of Financial Instruments	The following is a summary of financial instruments (in thousands): As of December 31, 2018 Gross Gross Unrealized Unrealized Estimated Fair Cost Gains Losses Values Available-for sale securities Commercial paper $ 10,173 $ - $ (9 ) $ 10,164 Money market funds 403 - - 403 Corporate bonds 52,448 - (114 ) 52,334 U.S. government securities 1,972 - - 1,972 Total available-for-sale securities $ 64,996 $ - $ (123 ) $ 64,873 Reported in: Cash and cash equivalents $ 4,143 Short-term investments 60,730 Total available-for-sale securities $ 64,873 As of December 31, 2017 Gross Gross Unrealized Unrealized Estimated Fair Cost Gains Losses Values Available-for sale securities Commercial paper $ 13,927 $ - $ (11 ) $ 13,916 Money market funds 1,269 - - 1,269 Corporate bonds 36,534 - (81 ) 36,453 U.S. government securities 2,489 - (4 ) 2,485 Total available-for-sale securities $ 54,219 $ - $ (96 ) $ 54,123 Reported in: Cash and cash equivalents $ 5,761 Short-term investments 48,362 Total available-for-sale securities $ 54,123
Summary of Contractual Maturities of Available-for-sale Securities	The contractual maturities of available-for-sale securities are presented in the following table (in thousands): December 31, 2018 Amortized Cost Basis Estimated Fair Value Due in one year or less $ 60,434 $ 60,313 Due between one and five years 4,562 4,560 $ 64,996 $ 64,873

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Schedule of Financial Assets Measured at Fair Value on a Recurring Basis	The following tables represent the Company’s financial assets measured at fair value on a recurring basis categorized by the fair value hierarchy as of December 31, 2018 and 2017 (in thousands): As of December 31, 2018 Level 1 Level 2 Level 3 Total Financial asset— available-for-sales securities Money market funds $ 403 $ - $ - $ 403 Commercial paper - 10,164 - 10,164 Corporate bonds - 52,334 - 52,334 U.S. government securities - 1,972 - 1,972 Total financial asset—available-for-sales securities $ 403 $ 64,470 $ - $ 64,873 As of December 31, 2017 Level 1 Level 2 Level 3 Total Financial asset— available-for-sales securities Money market funds $ 1,269 $ - $ - $ 1,269 Commercial paper - 13,916 - 13,916 Corporate bonds - 36,453 - 36,453 U.S. government securities - 2,485 - 2,485 Total financial asset—available-for-sales securities $ 1,269 $ 52,854 $ - $ 54,123
Summary of Changes in the Fair Value of the Company's Level 3 Financial Liabilities	the summary of changes in the fair value of the Company’s Level 3 financial liabilities was as follows (in thousands): Balance as of December 31, 2016 $ 12,885 Change in fair value of convertible preferred stock warrant liability 990 Exercise of Series H convertible preferred stock warrants (10,738 ) Conversion of convertible preferred stock warrants to common stock warrants upon IPO (3,137 ) Balance as of December 31, 2017 $ -
Summary of Outstanding Common Stock Warrants Converted from Convertible Preferred Stock Warrants Upon Closing of IPO	As of December 31, 2018, the Company has the following outstanding common stock warrants, which were converted from convertible preferred stock warrants upon the closing of the IPO in November 2017 (in thousands except per share data): As of December 31, 2018 Exercise Price Common Shares Converted from Per Share Expiration Date Underlying Warrants Series G $ 14.314298 12/16/2024 64,012 Series G/H $ 14.314298 1/30/2025 19,683 Total Common Stock Warrants 83,695
Schedule of Assumptions Used to Determine Fair Value of Convertible Preferred Stock	The assumptions used to determine the fair value of convertible preferred stock warrants relate to the weighted average assumptions from January 1, 2017 through November 3, 2017, when the convertible preferred stock warrants were converted into common stock warrants and for the year ended December 31, 2016 were as follows: Period from January 1, 2017 through November 3, 2017 Year ended December 31, 2016 Valuation method Black-Scholes Pricing Model Black-Scholes Pricing Model Risk-free interest rate 0.89%-2.24% 0.39%-2.25% Expected term 0.4 - 7.9 yrs 0.3 - 9.0 yrs Expected dividends 0% 0% Volatility 25% - 35% 25% - 50% Fair value of preferred stock: Convertible preferred Series A $ 9.00 $ 4.40 Convertible preferred Series B 9.00 7.30 Convertible preferred Series C-1 9.00 7.30 Convertible preferred Series D 9.00 7.80 Convertible preferred Series E 9.00 7.70 Convertible preferred Series F 9.00 9.10 Convertible preferred Series G 9.00 14.00 Convertible preferred Series H 9.00 14.30

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2018
Commitments And Contingencies Disclosure [Abstract]
Schedule of Future Minimum Operating Lease Payments and Purchase Obligations	As of December 31, 2018, future minimum operating lease payments and purchase obligations are as follows (in thousands): Total Operating Purchase Lease and Purchase Leases Obligations Obligations 2019 $ 1,482 $ 15,674 $ 17,156 2020 1,516 4,247 5,763 2021 1,993 1,008 3,001 2022 2,033 - 2,033 2023 and thereafter 2,217 - 2,217 Total $ 9,241 $ 20,929 $ 30,170

Common Stock and Share-based _2

Common Stock and Share-based Compensation (Tables)	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Summary of Stock Options Granted under Equity Incentive Plans	Activity of stock options granted under the Company’s equity incentive plans is set forth below: Weighted- Weighted Average Average Remaining Aggregate Number of Exercise Contractual Intrinsic Value Shares Price Term (Years) (in thousands) Balance—January 1, 2016 4,827,785 $ 2.38 7.2 $ 9,759 Granted 570,939 $ 4.32 Exercised (2,459,180 ) $ 1.85 Canceled (32,948 ) $ 3.11 Balance—December 31, 2016 2,906,596 $ 3.20 8.1 $ 4,941 Granted 1,320,382 $ 7.08 Exercised (388,621 ) $ 3.28 Canceled (104,813 ) $ 4.53 Balance—December 31, 2017 3,733,544 $ 4.53 7.9 $ 25,386 Granted 1,000 $ 13.89 Exercised (825,150 ) $ 3.38 Canceled (611,991 ) $ 6.23 Balance—December 31, 2018 2,297,403 $ 4.49 6.9 $ 9,858 Vested and exercisable—December 31, 2018 1,547,754 $ 3.74 6.5 $ 7,803 Vested and exercisable—December 31, 2017 1,648,917 $ 2.89 6.7 $ 13,924
Summary of Outstanding and Exercisable Options by Range of Exercise Prices	Outstanding options and exercisable options information by range of exercise prices as of December 31, 2018 was as follows: Outstanding Options Exercisable Options Weighted Average Remaining Weighted Weighted Range of Number of Contractual Term Average Number of Average Exercise Prices Shares (in Years) Exercise Price Shares Exercise Price $ 1.10 to $ 1.90 52,200 1.8 $ 1.50 52,200 $ 1.50 $ 2.00 to $ 3.90 961,800 6.0 $ 2.78 961,800 $ 2.78 $ 4.30 to $ 7.10 1,234,953 7.8 $ 5.76 1,167,626 $ 5.84 $ 8.61 to $ 9.90 47,450 8.7 $ 9.33 33,012 $ 9.65 $ 9.91 to $ 13.89 1,000 9.3 $ 13.89 1,000 $ 13.89 Total 2,297,403 6.9 $ 4.49 2,215,638 $ 4.47
Schedule of Fair Value Assumptions for Option Grants	The calculated fair value of option grants was estimated using the Black-Scholes model with the following assumptions for which options were granted: Year ended December 31, 2018 2017 2016 Risk-free interest rate 2.87 % 1.89%-2.40% 1.46%-2.43% Expected term 6.1 yrs 6.1 - 10 yrs 6.1 - 10 yrs Expected dividends 0 % 0 % 0 % Volatility 35 % 26% - 30% 30% - 34%
Summary of RSU Granted under Company's Equity Incentive Plans	Activity of RSU granted under the Company’s equity incentive plans is set forth below: Weighted Average Market Number of Units Value Balance—January 1, 2017 - $ - Granted 35,029 $ 10.56 Released - $ - Canceled - $ - Balance—December 31, 2017 35,029 $ 10.56 Granted 1,657,237 $ 12.76 Released (24,929 ) $ 11.53 Canceled (113,248 ) $ 13.01 Balance—December 31, 2018 1,554,089 $ 12.73
Schedule of Stock-Based Compensation Expense	Stock-based compensation expense recognized in the consolidated statements of operations and comprehensive loss was as follows (in thousands): Year ended December 31, 2018 2017 2016 Cost of revenue $ 156 $ 47 $ 31 Research and development 3,793 973 489 Sales and marketing 843 197 95 General and administrative 1,728 456 324 Total $ 6,520 $ 1,673 $ 939

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Summary of Domestic and Foreign Components of Income (Loss) Before Income Taxes	The following table represents domestic and foreign components of income (loss) before income taxes for the periods presented (in thousands): Year Ended December 31, 2018 2017 2016 Domestic $ (5,475 ) $ 4,195 $ (992 ) Foreign (3,822 ) (9,729 ) 715 Total $ (9,297 ) $ (5,534 ) $ (277 )
Summary of Provision for (Benefit from) Income Taxes	The Company’s provision for (benefit from) income taxes was as follows (in thousands): Year Ended December 31, 2018 2017 2016 Current: Federal $ - $ - $ (63 ) State 1 1 1 Foreign 474 (118 ) 230 Total current: 475 (117 ) 168 Deferred: Federal - - - State - - - Foreign - - - Total deferred benefit: - - - Total provision for (benefit from) income taxes $ 475 $ (117 ) $ 168
Summary of Reconciliation of Statutory Federal Income Tax Rate to Company's Effective Income Tax Rate	Reconciliation of the statutory federal income tax rate to the Company’s effective income tax rate is as follows: Year Ended December 31, 2018 2017 2016 Federal tax at statutory rate 21 % 34 % 34 % Foreign taxes (14 ) (58 ) 5 State taxes 7 (2 ) 316 Change in warrant valuation - (6 ) (66 ) Stock-based compensation 1 (5 ) (80 ) Research and development credit 22 14 343 Changes in reserves for uncertain tax positions (18 ) 3 (731 ) Change in valuation allowance (17 ) 283 114 2017 Tax Cut and Jobs Act impact - (283 ) - Tax effect upon adoption of ASU 2016-09 - 19 - GILTI inclusion (3 ) - - Other (4 ) 3 4 Total (5 ) % 2 % (61 ) %
Summary of Significant Components of Company's Net Deferred Tax Assets	Significant components of the Company’s net deferred tax assets were as follows (in thousands): Year Ended December 31, 2018 2017 Deferred tax assets: Net operating loss carryforwards $ 29,311 $ 31,286 Tax credit carryforwards 12,376 9,439 Accruals recognized in different periods 1,041 1,115 Fixed assets depreciation 381 137 Stock-based compensation 734 113 Other 96 22 Gross deferred tax assets: 43,939 42,112 Deferred tax liabilities: Other (135 ) (81 ) Subtotal 43,804 42,031 Valuation allowance (43,804 ) (42,031 ) Total net deferred tax assets $ - $ -
Summary of Reconciliation of Beginning and Ending Balances of Gross Unrecognized Tax Benefits	Reconciliation of the beginning and ending balances of the gross unrecognized tax benefits during the years ended December 31, 2018, 2017 and 2016 were as follows (in thousands): Year Ended December 31, 2018 2017 2016 Unrecognized benefits - beginning of period $ 7,047 $ 4,323 $ 4,100 Increases in balances related to tax positions taken during a prior period 1,783 2,567 - Increases in balances related to tax positions taken during the current period - 1,276 224 Decreases in balances related to tax positions taken during a prior period (58 ) (1,119 ) (1 ) Unrecognized benefits - end of period $ 8,772 $ 7,047 $ 4,323

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Summary of Computation of Basic and Diluted Net Loss Per Share Attributable to Common Shareholders	The following table summarizes the computation of basic and diluted net loss per share (in thousands, except share and per share data): Year Ended December 31, 2018 2017 2016 Net loss $ (9,772 ) $ (5,417 ) $ (445 ) Weighted-average common shares outstanding 34,181,200 9,204,384 4,240,461 Less: Shares subject to repurchase - - - Weighted-average shares outstanding 34,181,200 9,204,384 4,240,461 Net loss per share, basic and diluted $ (0.29 ) $ (0.59 ) $ (0.10 )
Summary of Potentially Dilutive Securities Outstanding Excluded from Computation of Diluted Weighted-average Shares Outstanding	The following potentially dilutive securities outstanding have been excluded from the computation of diluted weighted-average shares outstanding because such securities have an antidilutive impact due to losses reported (in common stock equivalent shares): As of December 31, 2018 2017 2016 Stock options to purchase common stock 2,297,403 3,733,544 2,831,850 Unvested restricted stock units 1,554,089 35,029 - Convertible preferred stock - - 19,833,843 Common stock warrants 83,695 584,148 1,559,764 Total 3,935,187 4,352,721 24,225,457

Segment Reporting (Tables)

Segment Reporting (Tables)	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Schedule of Revenue from Segments	The following table summarizes revenue by market (in thousands): Year Ended December 31, 2018 2017 2016 Revenue by market: Data Center $ 63,549 $ 64,781 $ 64,024 Enterprise Infrastructure 42,482 35,208 22,476 Access 14,094 3,132 175 Automotive 659 250 - Total revenue $ 120,784 $ 103,371 $ 86,675
Schedule of Geographical Distribution of Revenue	The geographical distribution of revenue as a percentage of total revenue for the periods indicated was as follows: Year Ended December 31, 2018 2017 2016 Malaysia 58 % 61 % 69 % China 26 30 26 United States 2 1 1 Other 14 8 4 Total 100 % 100 % 100 %

Concentrations (Tables)

Concentrations (Tables)	12 Months Ended
	Dec. 31, 2018
Risks And Uncertainties [Abstract]
Schedule of Customer Concentration as Percentage of Accounts Receivable and Total Revenue	Revenue and accounts receivables concentrated with significant customers and their manufacturing subcontractors, as a percentage of total revenue and accounts receivable was as follows: As of December 31, 2018 2017 Accounts Receivable: Customer A 42 % 49 % Customer B 19 34 Year Ended December 31, 2018 2017 2016 Revenue: Customer A 49 % 60 % 68 % Customer B 27 28 21

Organization, Description of _2

Organization, Description of Business and Basis for Presentation - Additional Information (Details) $ / shares in Units, $ in Thousands	Nov. 07, 2017USD ($)$ / sharesshares	Sep. 30, 2017	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)shares	Dec. 31, 2016USD ($)
Subsidiary Sale of Stock [Line Items]
Net proceeds from IPO				$ 65,627
Offering expense			$ 438	2,875	$ 2,404
Proceeds used to repay outstanding indebtedness				19,161	$ 6,560
Description of the reverse stock split arrangement			1-for-10 reverse split
Ratio applied to the conversion of stock split		0.10
Accumulated deficit			$ 207,446	$ 197,709
Common Stock
Subsidiary Sale of Stock [Line Items]
Number of shares issued | shares				7,840,700
IPO
Subsidiary Sale of Stock [Line Items]
Net proceeds from IPO	$ 65,600
Underwriting discounts and commissions	4,900
Offering expense	5,700
Proceeds used to repay outstanding indebtedness	9,200
Line of credit termination fee	$ 300
IPO | Common Stock
Subsidiary Sale of Stock [Line Items]
Number of shares issued | shares	7,840,700
Offering price per share | $ / shares	$ 9
IPO | Common Stock | Underwriters
Subsidiary Sale of Stock [Line Items]
Number of shares issued | shares	1,022,700

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Summary Of Significant Accounting Policy [Line Items]
Allowance for doubtful accounts receivable	$ 0
Accrued liabilities	300,000
Accumulated other comprehensive loss	123,000	$ 96,000
ASU 2014-09
Summary Of Significant Accounting Policy [Line Items]
Deferred revenue balance to retained earnings upon adoption of new standard	$ 100,000
Minimum
Summary Of Significant Accounting Policy [Line Items]
Standard product warranty	1 year
Minimum | ASU 2016-02
Summary Of Significant Accounting Policy [Line Items]
Lease, right-of-use assets	$ 5,500,000
Lease liabilities	$ 6,500,000
Maximum
Summary Of Significant Accounting Policy [Line Items]
Standard product warranty	3 years
Maximum | ASU 2016-02
Summary Of Significant Accounting Policy [Line Items]
Lease, right-of-use assets	$ 6,500,000
Lease liabilities	$ 7,500,000
Patents and IP License | Minimum
Summary Of Significant Accounting Policy [Line Items]
Intangible assets, estimated useful life	7 years
Patents and IP License | Maximum
Summary Of Significant Accounting Policy [Line Items]
Intangible assets, estimated useful life	12 years
IPO
Summary Of Significant Accounting Policy [Line Items]
Total deferred offering costs	$ 5,700,000

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Inventories (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Inventory Disclosure [Abstract]
Processed wafers	$ 1,233	$ 3,523
Work in process	5,990	10,118
Finished goods	7,251	4,828
Total inventories	$ 14,474	$ 18,469

Balance Sheet Components - Sc_2

Balance Sheet Components - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Prepaid Expense And Other Assets Current [Abstract]
Processed wafer prepayments	$ 67	$ 3,443
Electronic design automation tools	444	519
Other prepaid and other current assets	1,507	1,661
Total other prepaid and other current assets	$ 2,018	$ 5,623

Balance Sheet Components - Sc_3

Balance Sheet Components - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 26,661	$ 23,142
Less: accumulated depreciation and amortization	(17,436)	(13,169)
Property and equipment, net	9,225	9,973
Machinery and Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 15,237	13,268
Machinery and Equipment | Minimum
Property Plant And Equipment [Line Items]
Property and equipment, estimated useful lives	2 years
Machinery and Equipment | Maximum
Property Plant And Equipment [Line Items]
Property and equipment, estimated useful lives	3 years
Production Masks
Property Plant And Equipment [Line Items]
Property and equipment, estimated useful lives	4 years
Property and equipment, gross	$ 5,401	5,401
Software and Computer Equipment
Property Plant And Equipment [Line Items]
Property and equipment, estimated useful lives	3 years
Property and equipment, gross	$ 4,492	3,820
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment, estimated useful lives	Shorter of estimated life of asset or remaining lease term
Property and equipment, gross	$ 1,414	539
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Property and equipment, estimated useful lives	3 years
Property and equipment, gross	$ 117	$ 114

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Balance Sheets Components [Abstract]
Depreciation and amortization of property and equipment	$ 5	$ 3.9	$ 2.7
Amortization of intangible assets	$ 0.8	$ 0.8	$ 0.3

Balance Sheet Components - Sc_4

Balance Sheet Components - Schedule of Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Finite Lived Intangible Assets [Line Items]
Intangible assets, gross	$ 5,764	$ 5,764
Less: accumulated amortization	(2,016)	(1,208)
Intangible assets, net	$ 3,748	4,556
IP license
Finite Lived Intangible Assets [Line Items]
Intangible assets, estimated useful lives	7 years
Intangible assets, gross	$ 5,416	5,416
Patents
Finite Lived Intangible Assets [Line Items]
Intangible assets, gross	$ 348	$ 348
Patents | Minimum
Finite Lived Intangible Assets [Line Items]
Intangible assets, estimated useful lives	10 years
Patents | Maximum
Finite Lived Intangible Assets [Line Items]
Intangible assets, estimated useful lives	12 years

Balance Sheet Components - Sc_5

Balance Sheet Components - Schedule of Amortization Expense Related to Amortizable Intangibles In Future Periods (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Finite Lived Intangible Assets Future Amortization Expense [Abstract]
2,019	$ 808
2,020	808
2,021	808
2,022	800
2023 and thereafter	524
Intangible assets, net	$ 3,748	$ 4,556

Balance Sheet Components - Sc_6

Balance Sheet Components - Schedule of Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Accrued Liabilities Current [Abstract]
Accrued compensation and related benefits	$ 5,301	$ 5,242
Customer deposit	40	1,154
Accrued IP license fees	4,829	343
Accrued technical consulting and professional services	412	259
Accrued royalty, rebates, and commission	443	287
Other accrued liabilities	2,882	1,932
Total accrued liabilities	$ 13,907	$ 9,217

Financial Instruments - Summary

Financial Instruments - Summary of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Schedule Of Available For Sale Securities [Line Items]
Cost	$ 64,996	$ 54,219
Gross Unrealized Losses	(123)	(96)
Estimated Fair Values	64,873	54,123
Commercial Paper
Schedule Of Available For Sale Securities [Line Items]
Cost	10,173	13,927
Gross Unrealized Losses	(9)	(11)
Estimated Fair Values	10,164	13,916
Money Market Fund
Schedule Of Available For Sale Securities [Line Items]
Cost	403	1,269
Estimated Fair Values	403	1,269
Corporate Bonds
Schedule Of Available For Sale Securities [Line Items]
Cost	52,448	36,534
Gross Unrealized Losses	(114)	(81)
Estimated Fair Values	52,334	36,453
U.S. Government Securities
Schedule Of Available For Sale Securities [Line Items]
Cost	1,972	2,489
Gross Unrealized Losses		(4)
Estimated Fair Values	1,972	2,485
Cash and Cash Equivalents
Schedule Of Available For Sale Securities [Line Items]
Estimated Fair Values	4,143	5,761
Short-term Investments
Schedule Of Available For Sale Securities [Line Items]
Estimated Fair Values	$ 60,730	$ 48,362

Financial Instruments - Summa_2

Financial Instruments - Summary of Contractual Maturities of Available-for-sale Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Amortized Cost Basis
Due in one year or less	$ 60,434
Due between one and five years	4,562
Cost	64,996	$ 54,219
Estimated Fair Values
Due in one year or less	60,313
Due between one and five years	4,560
Total	$ 64,873	$ 54,123

Financial Instruments - Additio

Financial Instruments - Additional Information (Details) $ in Millions	Dec. 31, 2018USD ($)
Investments Debt And Equity Securities [Abstract]
Available for sale securities, continuous loss position, 12 months or longer	$ 19.2

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Financial Assets Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial asset—available-for-sales securities	$ 64,873	$ 54,123
Corporate Bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial asset—available-for-sales securities	52,334	36,453
Recurring Basis
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial asset—available-for-sales securities	64,873	54,123
Recurring Basis | Money Market Fund
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial asset—available-for-sales securities	403	1,269
Recurring Basis | Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial asset—available-for-sales securities	10,164	13,916
Recurring Basis | U.S. Government Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial asset—available-for-sales securities	1,972	2,485
Recurring Basis | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial asset—available-for-sales securities	403	1,269
Recurring Basis | Level 1 | Money Market Fund
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial asset—available-for-sales securities	403	1,269
Recurring Basis | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial asset—available-for-sales securities	64,470	52,854
Recurring Basis | Level 2 | Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial asset—available-for-sales securities	10,164	13,916
Recurring Basis | Level 2 | U.S. Government Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial asset—available-for-sales securities	1,972	2,485
Recurring Basis | Corporate Bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial asset—available-for-sales securities	52,334	36,453
Recurring Basis | Corporate Bonds | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial asset—available-for-sales securities	$ 52,334	$ 36,453

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Changes in the Fair Value of the Company's Level 3 Financial Liabilities (Details) - Level 3 $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 12,885
Change in fair value of convertible preferred stock warrant liability	990
Conversion of convertible preferred stock warrants to common stock warrants upon IPO	(3,137)
Series H Convertible Preferred Stock Warrants
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Exercise of convertible preferred stock warrants	$ (10,738)

Fair Value Measurements - Sum_2

Fair Value Measurements - Summary of Outstanding Common Stock Warrants Converted from Convertible Preferred Stock Warrants Upon Closing of IPO (Details)	12 Months Ended
	Dec. 31, 2018$ / sharesshares
Class Of Warrant Or Right [Line Items]
Common Shares Underlying Warrants	83,695
Series G Common Stock Warrants
Class Of Warrant Or Right [Line Items]
Warrants to purchase common stock, exercise price | $ / shares	$ 14.314298
Expiration Date	Dec. 16, 2024
Common Shares Underlying Warrants	64,012
Series G or Series H Common Stock Warrants
Class Of Warrant Or Right [Line Items]
Warrants to purchase common stock, exercise price | $ / shares	$ 14.314298
Expiration Date	Jan. 30, 2025
Common Shares Underlying Warrants	19,683

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details)	Mar. 25, 2015USD ($)$ / sharesshares	Jan. 30, 2015USD ($)$ / sharesshares	Dec. 16, 2014USD ($)$ / sharesshares	Apr. 05, 2013$ / sharesshares	Nov. 30, 2009$ / sharesshares	Dec. 31, 2018USD ($)$ / sharesshares	Dec. 31, 2017USD ($)shares	Dec. 31, 2016USD ($)	Dec. 31, 2013shares	Dec. 31, 2010USD ($)shares	Dec. 31, 2009shares
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Transfers within hierarchy | $						$ 0	$ 0
Total Other Income (Expense)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Gain (loss) on fair value of convertible preferred stock warrants | $							$ (1,000,000)	$ (500,000)
Series G Convertible Preferred Stock Warrants
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrant exercise price | $ / shares						$ 14.314298
Warrant expiration date						Dec. 16, 2024
Series G or Series H Convertible Preferred Stock Warrants
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrant exercise price | $ / shares						$ 14.314298
Warrant expiration date						Jan. 30, 2025
Pinnacle Ventures | Series A Convertible Preferred Stock | Series A Convertible Preferred Stock Warrants
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants issued						33,499
Warrant exercise price | $ / shares						$ 8.209000
Pinnacle Ventures | Series B Convertible Preferred Stock | Series B Convertible Preferred Stock Warrants
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants issued					12,556	15,753
Warrant exercise price | $ / shares						$ 21.502753
Warrant expiration period						10 years
Warrant expired, year						2,018
Pinnacle Ventures | Series B Convertible Preferred Stock | Series D Convertible Preferred Stock Warrants
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants issued					12,556
Pinnacle Ventures | Series D Convertible Preferred Stock | Series B Convertible Preferred Stock Warrants
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants issued					40,516
Warrant exercise price | $ / shares					$ 6.663973
Pinnacle Ventures | Series D Convertible Preferred Stock | Series D Convertible Preferred Stock Warrants
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants issued					40,516	21,008				21,008
Warrant exercise price | $ / shares					$ 6.663973
Warrant expiration period					10 years
Warrants exercised, year						2,018
Borrowings | $										$ 3,500,000
Pinnacle Ventures | Series F Convertible Preferred Stock | Series F Convertible Preferred Stock Warrants
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants issued				64,655
Warrant exercise price | $ / shares				$ 9.280000
Warrants exercised, year				2,018
Warrant expiration date				Apr. 30, 2023
Pinnacle Ventures | Series G Convertible Preferred Stock | Series G Convertible Preferred Stock Warrants
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants issued			64,012
Warrant exercise price | $ / shares			$ 14.314298
Warrant expiration date			Dec. 31, 2024
Pinnacle Ventures | Series G Convertible Preferred Stock | Series G Convertible Preferred Stock Warrants | Monte Carlo Simulation
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value | $			$ 173,091
Pinnacle Ventures | Series G Convertible Preferred Stock | Series G Convertible Preferred Stock Warrants | Measurement Input, Risk Free Interest Rate | Monte Carlo Simulation
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants measurement input			0.0213
Pinnacle Ventures | Series G Convertible Preferred Stock | Series G Convertible Preferred Stock Warrants | Measurement Input, Expected Term | Monte Carlo Simulation
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contractual term			9 years 8 months 15 days
Pinnacle Ventures | Series G Convertible Preferred Stock | Series G Convertible Preferred Stock Warrants | Measurement Input, Price Volatility | Monte Carlo Simulation
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants measurement input			0.5
Intel Corporation | Series C-1 Convertible Preferred Stock | Series C-1 Convertible Preferred Stock Warrants
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants issued					347,208		53,400
Preferred shares, vested											1,927,505
Preferred shares underlying warrants									100,000
Intel Corporation | Series C-1 Convertible Preferred Stock | Series C-1 Convertible Preferred Stock Warrants | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants issued						400,608
Warrant exercise price | $ / shares						$ 0.10
Warrants exercised, year						2,018
Hercules Technology Growth Capital | Series G or Series H Convertible Preferred Stock Warrants
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants issued		19,683
Warrant exercise price | $ / shares		$ 14.314298
Warrant expiration date		Jan. 31, 2025
Line of credit facility | $		$ 11,500,000
Hercules Technology Growth Capital | Series G or Series H Convertible Preferred Stock Warrants | Monte Carlo Simulation
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value | $		$ 50,000
Hercules Technology Growth Capital | Series G or Series H Convertible Preferred Stock Warrants | Measurement Input, Risk Free Interest Rate | Monte Carlo Simulation
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants measurement input		0.0206
Hercules Technology Growth Capital | Series G or Series H Convertible Preferred Stock Warrants | Measurement Input, Expected Term | Monte Carlo Simulation
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contractual term		9 years 9 months 29 days
Hercules Technology Growth Capital | Series G or Series H Convertible Preferred Stock Warrants | Measurement Input, Price Volatility | Monte Carlo Simulation
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants measurement input		0.50
GLOBALFOUNDRIES U.S. Inc | Series G Or Series H Convertible Preferred Stock | Series G or Series H Convertible Preferred Stock Warrants
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants issued	975,616
Warrant exercise price | $ / shares	$ 0.10
Warrant expiration date	Mar. 31, 2025
Fair value | $	$ 12,000,000
Warrant exercise date	2017-05
GLOBALFOUNDRIES U.S. Inc | Series G Or Series H Convertible Preferred Stock | Series G or Series H Convertible Preferred Stock Warrants | Measurement Input, Risk Free Interest Rate
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants measurement input	0.0103
GLOBALFOUNDRIES U.S. Inc | Series G Or Series H Convertible Preferred Stock | Series G or Series H Convertible Preferred Stock Warrants | Measurement Input, Expected Term
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contractual term	1 year
GLOBALFOUNDRIES U.S. Inc | Series G Or Series H Convertible Preferred Stock | Series G or Series H Convertible Preferred Stock Warrants | Measurement Input, Price Volatility
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants measurement input	0.35
GLOBALFOUNDRIES U.S. Inc | Series G Or Series H Convertible Preferred Stock | Series G or Series H Convertible Preferred Stock Warrants | Measurement Input, Expected Dividend Rate
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants measurement input	0

Fair Value Measurements - Sch_2

Fair Value Measurements - Schedule of Assumptions Used to Determine Fair Value of Convertible Preferred Stock (Details) - Convertible Preferred Stock Warrants [Member]	Nov. 03, 2017$ / shares	Dec. 31, 2016$ / shares
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Alternative Investment, Valuation Technique [Extensible List]	aq:BlackScholesPricingModelMember	aq:BlackScholesPricingModelMember
Measurement Input, Risk Free Interest Rate | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Warrants measurement input	0.89	0.39
Measurement Input, Risk Free Interest Rate | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Warrants measurement input	2.24	2.25
Measurement Input, Expected Term | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Warrants expected term	4 months 24 days	3 months 19 days
Measurement Input, Expected Term | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Warrants expected term	7 years 10 months 25 days	9 years
Measurement Input, Expected Dividend Rate
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Warrants measurement input	0	0
Measurement Input, Price Volatility | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Warrants measurement input	25	25
Measurement Input, Price Volatility | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Warrants measurement input	35	50
Measurement Input, Exercise Price | Convertible Preferred Series A
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Warrants measurement input	9	4.40
Measurement Input, Exercise Price | Convertible Preferred Series B
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Warrants measurement input	9	7.30
Measurement Input, Exercise Price | Convertible Preferred Series C-1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Warrants measurement input	9	7.30
Measurement Input, Exercise Price | Convertible Preferred Series D
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Warrants measurement input	9	7.80
Measurement Input, Exercise Price | Convertible Preferred Series E
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Warrants measurement input	9	7.70
Measurement Input, Exercise Price | Convertible Preferred Series F
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Warrants measurement input	9	9.10
Measurement Input, Exercise Price | Convertible Preferred Series G
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Warrants measurement input	9	14
Measurement Input, Exercise Price | Convertible Preferred Series H
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Warrants measurement input	9	14.30

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Commitments And Contingencies Disclosure [Abstract]
Rent expense	$ 1,900,000	$ 1,200,000	$ 900,000
Liability associated with indemnifications	$ 0	$ 0
Operating Leases, Indemnification Agreements, Description	Under the indemnification provisions of the Company’s standard sales related contracts, the Company agrees to defend its customers against third-party claims asserting infringement of certain intellectual property rights, which may include patents, copyrights, trademarks, or trade secrets and to pay judgments entered on such claims. Certain agreements include indemnification provisions that could potentially expose the Company to losses in excess of the amount received under the agreement. In addition, the Company indemnifies its directors and certain of its officers while they are serving in good faith in such capacities. To date, the Company has not incurred costs to defend lawsuits or settle claims related to these indemnification agreements

Commitments and Contingencies_2

Commitments and Contingencies - Schedule of Future Minimum Operating Lease Payments and Purchase Obligations (Details) $ in Thousands	Dec. 31, 2018USD ($)
Operating Leases
2,019	$ 1,482
2,020	1,516
2,021	1,993
2,022	2,033
2023 and thereafter	2,217
Total	9,241
Purchase Obligations
2,019	15,674
2,020	4,247
2,021	1,008
Total	20,929
Total Lease and Purchase Obligations
2,019	17,156
2,020	5,763
2,021	3,001
2,022	2,033
2023 and thereafter	2,217
Total	$ 30,170

Common Stock and Share-based _3

Common Stock and Share-based Compensation - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Nov. 30, 2017
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Common stock, shares authorized	95,000,000	400,000,000
Common stock, par value	$ 0.00001	$ 0.00001
Preferred stock, shares authorized	5,000,000	10,000,000
Preferred stock, par value	$ 0.00001	$ 0.00001
Preferred stock, shares outstanding	0	0
Dividends declared	$ 0
Preferred stock convertible into common stock	20,816,754
Unrecognized stock compensation costs	$ 2,000,000	$ 4,800,000
Unrecognized stock compensation costs recognition period	2 years 9 months 18 days	3 years 1 month 6 days
Aggregate intrinsic value of options exercised	$ 7,100,000	$ 1,600,000
Weighted-average grant-date fair value of options granted	$ 5.46	$ 2.94
Risk-free interest rate, minimum	2.87%	1.89%	1.46%
Risk-free interest rate, maximum		2.40%	2.43%
Expected term	6 years 1 month 6 days
Expected dividends	0.00%	0.00%	0.00%
Volatility	35.00%
Income tax benefit associated with stock-based compensation expense	$ 0	$ 0	$ 0
2015 Equity Incentive Plan and 2004 Equity Incentive Plan | Incentive Stock Options
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Exercise price determination description	The exercise price of an option is determined by the board of directors when the option is granted and may not be less than 85% of the fair market value of the shares on the date of grant, provided that the exercise price of an ISO is not less than 100% of the fair market value of the shares on the date of grant and the exercise price of any option granted to a 10% stockholder is not less than 110% of the fair market value of the shares on the date of grant.
Exercise price per share	85.00%
Equity incentive plan expiration period	10 years
2015 Equity Incentive Plan and 2004 Equity Incentive Plan | Nonstatutory Stock Options
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Equity incentive plan expiration period	10 years
2017 Equity Incentive Plan
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Vesting period	4 years
Common shares reserved	3,294,919
Percentage of increase in common shares reserved	5.00%
Shares available for grant	2,367,378
Description of restricted stock unit awards conversion basis upon vesting	one-for-one
Number of shares reduced from shares available for issuance upon restricted stock unit awards grants	1
2017 Equity Incentive Plan | Restricted Stock Unit Awards
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Vesting period	4 years
Unrecognized stock compensation costs recognition period	3 years	1 year 9 months 18 days
Unamortized compensation expense to be recognized	$ 15,800,000	$ 400,000
ESPP
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Common shares reserved	1,000,000
Shares available for grant	203,986
Unrecognized stock compensation costs recognition period	5 months	5 months
Common stock shares authorized				1,317,967
Percentage of shares of capital stock outstanding	2.00%
Percentage of payroll deduction on eligible compensation	15.00%
Percentage of shares purchased at fair market value of common stock	85.00%
Shares issued under plan	366,369
Risk-free interest rate, minimum	1.31%
Risk-free interest rate, maximum	2.36%
Expected term	6 months
Expected dividends	0.00%
Volatility	22.00%
Unamortized compensation expense to be recognized	$ 500,000	$ 500,000
Share-based Compensation Award, Tranche One | 2015 Equity Incentive Plan and 2004 Equity Incentive Plan | Incentive Stock Options
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Vesting percentage	25.00%
Vesting period	12 months
Share-based Compensation Award, Tranche Two | 2015 Equity Incentive Plan and 2004 Equity Incentive Plan | Incentive Stock Options
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Vesting percentage	25.00%
Vesting period	12 months
Share-based Compensation Award, Tranche Three | 2015 Equity Incentive Plan and 2004 Equity Incentive Plan | Incentive Stock Options
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Vesting percentage	25.00%
Vesting period	12 months
Share Based Compensation Award Tranche Four | 2015 Equity Incentive Plan and 2004 Equity Incentive Plan | Incentive Stock Options
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Vesting percentage	25.00%
Vesting period	12 months
Convertible Preferred Stock
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Preferred stock, shares outstanding	0	0
Maximum
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Common stock, shares authorized	95,000,000	400,000,000
Expected term		10 years	10 years
Maximum | 2015 Equity Incentive Plan and 2004 Equity Incentive Plan | Incentive Stock Options
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Exercise price per share	100.00%
Maximum | 2015 Equity Incentive Plan and 2004 Equity Incentive Plan | Incentive Stock Options | 10% stockholder
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Exercise price per share	110.00%
Maximum | 2017 Equity Incentive Plan
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Exercise price per share	100.00%
Options granted exercise period	10 years
Maximum | 2017 Equity Incentive Plan | 10% stockholder
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Exercise price per share	110.00%
Minimum
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Expected term		6 years 1 month 6 days	6 years 1 month 6 days

Common Stock and Share-based _4

Common Stock and Share-based Compensation - Summary of Stock Options Granted under Equity Incentive Plans (Details) - Incentive Stock Options - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Beginning balance	3,733,544	2,906,596	4,827,785
Granted	1,000	1,320,382	570,939
Exercised	(825,150)	(388,621)	(2,459,180)
Canceled	(611,991)	(104,813)	(32,948)
Ending balance	2,297,403	3,733,544	2,906,596	4,827,785
Vested and exercisable—December 31, 2018	1,547,754	1,648,917
Weighted average exercise price, beginning balance	$ 4.53	$ 3.20	$ 2.38
Weighted average exercise price, granted	13.89	7.08	4.32
Weighted average exercise price, exercised	3.38	3.28	1.85
Weighted average exercise price, canceled	6.23	4.53	3.11
Weighted average exercise price, ending balance	4.49	4.53	$ 3.20	$ 2.38
Weighted average exercise price, vested and exercisable	$ 3.74	$ 2.89
Weighted average remaining contractual term	6 years 10 months 24 days	7 years 10 months 24 days	8 years 1 month 6 days	7 years 2 months 12 days
Weighted average remaining contractual term, vested and exercisable	6 years 6 months	6 years 8 months 12 days
Aggregate intrinsic value	$ 9,858	$ 25,386	$ 4,941	$ 9,759
Aggregate intrinsic value, vested and exercisable	$ 7,803	$ 13,924

Common Stock and Share-based _5

Common Stock and Share-based Compensation - Summary of Outstanding and Exercisable Options by Range of Exercise Prices (Details)	12 Months Ended
	Dec. 31, 2018$ / sharesshares
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Number of Shares, Outstanding Options | shares	2,297,403
Weighted Average Remaining Contractual Term (in Years), Outstanding Options	6 years 10 months 24 days
Weighted Average Exercise Price, Outstanding Options	$ 4.49
Number of Shares, Exercisable options | shares	2,215,638
Weighted Average Exercise Price, Exercisable Options	$ 4.47
1.10 - 1.90
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Range of Exercise Prices, Lower Limit	1.10
Range of Exercise Prices, Upper Limit	$ 1.90
Number of Shares, Outstanding Options | shares	52,200
Weighted Average Remaining Contractual Term (in Years), Outstanding Options	1 year 9 months 18 days
Weighted Average Exercise Price, Outstanding Options	$ 1.50
Number of Shares, Exercisable options | shares	52,200
Weighted Average Exercise Price, Exercisable Options	$ 1.50
2.00 - 3.90
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Range of Exercise Prices, Lower Limit	2
Range of Exercise Prices, Upper Limit	$ 3.90
Number of Shares, Outstanding Options | shares	961,800
Weighted Average Remaining Contractual Term (in Years), Outstanding Options	6 years
Weighted Average Exercise Price, Outstanding Options	$ 2.78
Number of Shares, Exercisable options | shares	961,800
Weighted Average Exercise Price, Exercisable Options	$ 2.78
4.30 - 7.10
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Range of Exercise Prices, Lower Limit	4.30
Range of Exercise Prices, Upper Limit	$ 7.10
Number of Shares, Outstanding Options | shares	1,234,953
Weighted Average Remaining Contractual Term (in Years), Outstanding Options	7 years 9 months 18 days
Weighted Average Exercise Price, Outstanding Options	$ 5.76
Number of Shares, Exercisable options | shares	1,167,626
Weighted Average Exercise Price, Exercisable Options	$ 5.84
8.61 - 9.90
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Range of Exercise Prices, Lower Limit	8.61
Range of Exercise Prices, Upper Limit	$ 9.90
Number of Shares, Outstanding Options | shares	47,450
Weighted Average Remaining Contractual Term (in Years), Outstanding Options	8 years 8 months 12 days
Weighted Average Exercise Price, Outstanding Options	$ 9.33
Number of Shares, Exercisable options | shares	33,012
Weighted Average Exercise Price, Exercisable Options	$ 9.65
9.91 - 13.89
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Range of Exercise Prices, Lower Limit	9.91
Range of Exercise Prices, Upper Limit	$ 13.89
Number of Shares, Outstanding Options | shares	1,000
Weighted Average Remaining Contractual Term (in Years), Outstanding Options	9 years 3 months 18 days
Weighted Average Exercise Price, Outstanding Options	$ 13.89
Number of Shares, Exercisable options | shares	1,000
Weighted Average Exercise Price, Exercisable Options	$ 13.89

Common Stock and Share-based _6

Common Stock and Share-based Compensation - Schedule of Fair Value Assumptions for Option Grants (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate	2.87%
Risk-free interest rate, maximum		2.40%	2.43%
Expected term	6 years 1 month 6 days
Expected dividends	0.00%	0.00%	0.00%
Volatility	35.00%
Volatility, maximum		30.00%	34.00%
Risk-free interest rate, minimum	2.87%	1.89%	1.46%
Volatility, minimum	35.00%	26.00%	30.00%
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term		10 years	10 years
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term		6 years 1 month 6 days	6 years 1 month 6 days

Common Stock and Share-based _7

Common Stock and Share-based Compensation - Summary of RSU Granted under Company's Equity Incentive Plans (Details) - Restricted Stock Unit Awards - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Units, beginning balance	35,029
Number of Units, Granted	1,657,237	35,029
Number of Units, Released	(24,929)
Number of Units, Canceled	(113,248)
Number of Units, ending balance	1,554,089	35,029
Weighted Average Market Value, beginning balance	$ 10.56
Weighted Average Market Value, Granted	12.76	$ 10.56
Weighted Average Market Value, Released	11.53
Weighted Average Market Value, Canceled	13.01
Weighted Average Market Value, ending balance	$ 12.73	$ 10.56

Common Stock and Share-based _8

Common Stock and Share-based Compensation - Schedule of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 6,520	$ 1,673	$ 939
Cost of Revenue
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	156	47	31
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	3,793	973	489
Sales and Marketing
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	843	197	95
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 1,728	$ 456	$ 324

Income Taxes - Summary of Domes

Income Taxes - Summary of Domestic and Foreign Components of Income (Loss) Before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Domestic	$ (5,475)	$ 4,195	$ (992)
Foreign	(3,822)	(9,729)	715
Total	$ (9,297)	$ (5,534)	$ (277)

Income Taxes - Summary of Provi

Income Taxes - Summary of Provision for (Benefit from) Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current:
Federal			$ (63)
State	$ 1	$ 1	1
Foreign	474	(118)	230
Total current:	475	(117)	168
Deferred:
Total provision for (benefit from) income taxes	$ 475	$ (117)	$ 168

Income Taxes - Summary of Recon

Income Taxes - Summary of Reconciliation of Statutory Federal Income Tax Rate to Company's Effective Income Tax Rate (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Federal tax at statutory rate	21.00%	34.00%	34.00%
Foreign taxes	(14.00%)	(58.00%)	5.00%
State taxes	7.00%	(2.00%)	316.00%
Change in warrant valuation		(6.00%)	(66.00%)
Stock-based compensation	1.00%	(5.00%)	(80.00%)
Research and development credit	22.00%	14.00%	343.00%
Changes in reserves for uncertain tax positions	(18.00%)	3.00%	(731.00%)
Change in valuation allowance	(17.00%)	283.00%	114.00%
2017 Tax Cut and Jobs Act impact		(283.00%)
Tax effect upon adoption of ASU 2016-09		19.00%
GILTI inclusion	(3.00%)
Other	(4.00%)	3.00%	4.00%
Total	(5.00%)	2.00%	(61.00%)

Income Taxes - Summary of Signi

Income Taxes - Summary of Significant Components of Company's Net Deferred Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Net operating loss carryforwards	$ 29,311	$ 31,286
Tax credit carryforwards	12,376	9,439
Accruals recognized in different periods	1,041	1,115
Fixed assets depreciation	381	137
Stock-based compensation	734	113
Other	96	22
Gross deferred tax assets:	43,939	42,112
Deferred tax liabilities:
Other	(135)	(81)
Subtotal	43,804	42,031
Valuation allowance	$ (43,804)	$ (42,031)	$ (58,500)

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax [Line Items]
Federal tax at statutory rate	21.00%	34.00%	34.00%
Amount of deferred tax assets decreased		$ 15,700,000
Provisional amount recorded related to the remeasurement		0
Deferred tax assets, valuation allowance	$ 43,804,000	42,031,000	$ 58,500,000
Deferred tax assets, change in the valuation allowance	1,800,000	(16,500,000)	(3,200,000)
Federal net operating loss carryforwards	34,900,000
State net operating loss carryforwards	24,100,000
Federal research and development credits	1,800,000
Interest or penalty accruals	0	$ 0	$ 0
Federal
Income Tax [Line Items]
Net operating loss carryforwards	$ 175,700,000
NOL carryforwards begin to expire	2,025
Federal | Research and Development Tax Credit Carryforwards
Income Tax [Line Items]
Tax credit carryforwards	$ 8,900,000
Tax credit carryforwards begin to expire	2,026
State
Income Tax [Line Items]
Net operating loss carryforwards	$ 92,000,000
NOL carryforwards begin to expire	2,019
State | Research and Development Tax Credit Carryforwards
Income Tax [Line Items]
Tax credit carryforwards	$ 9,600,000
Tax credit carryforwards begin to expire, description	indefinitely
Maximum
Income Tax [Line Items]
Federal tax at statutory rate		35.00%
Minimum
Income Tax [Line Items]
Change in ownership percentage	50.00%

Income Taxes - Summary of Rec_2

Income Taxes - Summary of Reconciliation of Beginning and Ending Balances of Gross Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Unrecognized benefits - beginning of period	$ 7,047	$ 4,323	$ 4,100
Increases in balances related to tax positions taken during a prior period	1,783	2,567
Increases in balances related to tax positions taken during the current period		1,276	224
Decreases in balances related to tax positions taken during a prior period	(58)	(1,119)	(1)
Unrecognized benefits - end of period	$ 8,772	$ 7,047	$ 4,323

Net Loss Per Share - Summary of

Net Loss Per Share - Summary of Computation of Basic and Diluted Net Loss Per Share Attributable to Common Shareholders (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Earnings Per Share [Abstract]
Net loss	$ (9,772)	$ (5,417)	$ (445)
Weighted-average common shares outstanding	34,181,200	9,204,384	4,240,461
Weighted-average shares outstanding	34,181,200	9,204,384	4,240,461
Net loss per share, basic and diluted	$ (0.29)	$ (0.59)	$ (0.10)

Net Loss Per Share - Summary _2

Net Loss Per Share - Summary of Potentially Dilutive Securities Outstanding Excluded from Computation of Diluted Weighted-average Shares Outstanding (Details) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential dilutive securities outstanding excluded from computation of diluted weighted-average shares outstanding	3,935,187	4,352,721	24,225,457
Incentive Stock Options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential dilutive securities outstanding excluded from computation of diluted weighted-average shares outstanding	2,297,403	3,733,544	2,831,850
Unvested Restricted Stock Units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential dilutive securities outstanding excluded from computation of diluted weighted-average shares outstanding	1,554,089	35,029
Convertible Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential dilutive securities outstanding excluded from computation of diluted weighted-average shares outstanding			19,833,843
Common Stock Warrants
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential dilutive securities outstanding excluded from computation of diluted weighted-average shares outstanding	83,695	584,148	1,559,764

Segment Reporting (Details)

Segment Reporting (Details)	12 Months Ended
	Dec. 31, 2018Segment
Segment Reporting [Abstract]
Number of reportable segments	1

Segment Reporting - Schedule of

Segment Reporting - Schedule of Revenue from Segments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Revenue	$ 120,784	$ 103,371	$ 86,675
Data Center
Segment Reporting Information [Line Items]
Revenue	63,549	64,781	64,024
Enterprise Infrastructure
Segment Reporting Information [Line Items]
Revenue	42,482	35,208	22,476
Access
Segment Reporting Information [Line Items]
Revenue	14,094	3,132	$ 175
Automotive
Segment Reporting Information [Line Items]
Revenue	$ 659	$ 250

Segment Reporting - Schedule _2

Segment Reporting - Schedule of Geographical Distribution of Revenue (Details) - Revenue - Geographic Concentration Risk	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues From External Customers And Long Lived Assets [Line Items]
Percentage of revenue	100.00%	100.00%	100.00%
Malaysia
Revenues From External Customers And Long Lived Assets [Line Items]
Percentage of revenue	58.00%	61.00%	69.00%
China
Revenues From External Customers And Long Lived Assets [Line Items]
Percentage of revenue	26.00%	30.00%	26.00%
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Percentage of revenue	2.00%	1.00%	1.00%
Other
Revenues From External Customers And Long Lived Assets [Line Items]
Percentage of revenue	14.00%	8.00%	4.00%

Concentrations - Additional Inf

Concentrations - Additional Information (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Risks And Uncertainties [Abstract]
Amounts held on deposit at financial institutions in excess of FDIC insured limits	$ 1.1	$ 0.9	$ 28

Concentrations - Schedule of Cu

Concentrations - Schedule of Customer Concentration as Percentage of Accounts Receivable and Total Revenue (Details) - Customer Concentration Risk	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accounts Receivable | Customer A
Concentration Risk [Line Items]
Concentration risk, percentage	42.00%	49.00%
Accounts Receivable | Customer B
Concentration Risk [Line Items]
Concentration risk, percentage	19.00%	34.00%
Revenue | Customer A
Concentration Risk [Line Items]
Concentration risk, percentage	49.00%	60.00%	68.00%
Revenue | Customer B
Concentration Risk [Line Items]
Concentration risk, percentage	27.00%	28.00%	21.00%

Employee Benefit Plan - Additio

Employee Benefit Plan - Additional Information (Details)	12 Months Ended
	Dec. 31, 2018USD ($)
401 (k)
Defined Contribution Plan Disclosure [Line Items]
Company contribution	$ 0

Related Party Transaction - Add

Related Party Transaction - Additional Information (Details) - Significant Stockholder - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	May 31, 2018	Dec. 31, 2016	Dec. 31, 2017
Related Party Transaction [Line Items]
License agreement initial payment		$ 2
Due to related parties			$ 3.4
Minimum
Related Party Transaction [Line Items]
Beneficial ownership percentage of outstanding common stock	5.00%