ADESTO TECHNOLOGIES (IOTS) 10-Q 9 Nov 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - $ / shares	9 Months Ended
	Sep. 30, 2018	Oct. 26, 2018
Document and Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Trading Symbol	IOTS
Entity Registrant Name	ADESTO TECHNOLOGIES CORP
Entity Central Index Key	1,395,848
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Common Stock, Shares Outstanding		29,434,142
Entity Listing, Par Value Per Share	$ 0.0001

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands		Sep. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents		$ 13,273	$ 30,078	[1]
Short-term investments		1,275
Accounts receivable, net		24,706	8,668	[1]
Inventories		17,541	5,814	[1]
Prepaid expenses		1,853	993	[1]
Other current assets		1,971	52	[1]
Total current assets		60,619	45,605	[1]
Property and equipment, net		8,729	7,183	[1]
Intangible assets, net		38,013	7,102	[1]
Other non-current assets		1,594	900	[1]
Goodwill		38,640	22	[1]
Total assets		147,595	60,812	[1]
Current liabilities:
Accounts payable		16,316	7,075	[1]
Accrued compensation and benefits		3,701	2,614	[1]
Accrued expenses and other current liabilities		6,969	2,359	[1]
Price adjustments and other revenue reserves		5,202
Earn-out liability, current		9,997
Line of credit, current	[1]		1,500
Term loan, current	[1]		926
Total current liabilities		42,185	14,474	[1]
Term loan, non-current		29,433	10,908	[1]
Other non-current liabilities		3,788	75	[1]
Deferred rent, non-current		2,063	2,404	[1]
Deferred tax liability, non-current		1,797	1	[1]
Total liabilities		79,266	27,862	[1]
Commitments and contingencies (See Note 9)				[1]
Stockholders’ equity:
Preferred stock, $0.0001 par value, 5,000,000 shares authorized as of September 30, 2018 and December 31, 2017; no shares issued and outstanding as of September 30, 2018 and December 31, 2017				[1]
Common stock, $0.0001 par value, 100,000,000 shares authorized; 29,367,787 and 21,291,833 shares issued and outstanding as of September 30, 2018 and December 31, 2017, respectively		3	2	[1]
Additional paid-in capital		183,087	133,087	[1]
Accumulated other comprehensive loss		(360)	(295)	[1]
Accumulated deficit		(114,401)	(99,844)	[1]
Total stockholders’ equity		68,329	32,950	[1]
Total liabilities and stockholders’ equity		$ 147,595	$ 60,812	[1]
[1]	The condensed consolidated balance sheet as of December 31, 2017 was derived from the audited consolidated financial statements as of that date.

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Sep. 30, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued	29,367,787	21,291,833
Common stock, shares outstanding	29,367,787	21,291,833

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Revenue, net	$ 21,927	$ 15,239	$ 55,412	$ 39,958
Revenue, net, type	us-gaap:ProductMember us-gaap:ServiceMember	us-gaap:ProductMember us-gaap:ServiceMember	us-gaap:ProductMember us-gaap:ServiceMember	us-gaap:ProductMember us-gaap:ServiceMember
Cost of revenue	$ 12,344	$ 7,773	$ 30,885	$ 20,215
Cost of revenue, type	us-gaap:ProductMember us-gaap:ServiceMember	us-gaap:ProductMember us-gaap:ServiceMember	us-gaap:ProductMember us-gaap:ServiceMember	us-gaap:ProductMember us-gaap:ServiceMember
Gross profit	$ 9,583	$ 7,466	$ 24,527	$ 19,743
Operating expenses:
Research and development	5,620	3,606	13,706	10,653
Sales and marketing	4,256	2,897	10,623	8,408
General and administrative	7,130	1,761	12,484	5,569
Total operating expenses	17,006	8,264	36,813	24,630
Loss from operations	(7,423)	(798)	(12,286)	(4,887)
Other income (expense):
Interest expense, net	(1,046)	(170)	(2,368)	(581)
Other income (expense), net	8	(12)	17	2
Total other income (expense), net	(1,038)	(182)	(2,351)	(579)
Loss before provision for (benefit from) income taxes	(8,461)	(980)	(14,637)	(5,466)
Provision for (benefit from) income taxes	(64)	17	(80)	57
Net loss	$ (8,397)	$ (997)	$ (14,557)	$ (5,523)
Net loss per share:
Basic and diluted	$ (0.29)	$ (0.05)	$ (0.61)	$ (0.31)
Weighted average number of shares used in computing net loss per share:
Basic and diluted	28,171,952	21,058,635	23,717,727	17,701,230

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net loss	$ (8,397)	$ (997)	$ (14,557)	$ (5,523)
Other comprehensive loss, net of tax:
Foreign currency translation adjustment	(148)	(20)	(65)	(71)
Comprehensive loss	$ (8,545)	$ (1,017)	$ (14,622)	$ (5,594)

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Cash flows from operating activities:
Net loss	$ (14,557)	$ (5,523)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	2,103	2,873
Depreciation and amortization	1,687	1,004
Amortization of intangible assets	2,119	927
Amortization of debt discount	707	64
Deferred income taxes	(463)
Gain on investment	(1)
Gain on sale of equipment	(18)
Changes in assets and liabilities:
Accounts receivable	(12,826)	(2,699)
Inventories	(6,017)	919
Prepaid expenses and other current assets	949	116
Other non-current assets	(8)	(311)
Accounts payable	5,834	1,426
Accrued compensation and benefits	1,087	533
Accrued expenses and other current liabilities	1,178	(230)
Price adjustments and other revenue reserves	5,202
Other non-current liabilities	283
Deferred rent	(341)	(315)
Net cash used in operating activities	(13,082)	(1,216)
Cash flows from investing activities:
Acquisition of property and equipment	(2,631)	(2,054)
Investment in unconsolidated affiliate	(434)
Net cash used in investing activities	(66,517)	(2,054)
Cash flows from financing activities:
Proceeds from public offering, net of underwriting discounts and commissions	42,658	18,363
Proceeds from exercise of stock options and employee stock purchase plan	813	639
Tax withholdings related to net share settlement of restricted stock units	(372)	(157)
Proceeds from revolving line of credit		27,427
Payments on revolving line of credit	(1,500)	(27,234)
Proceeds from term loan, net of fees	33,591
Payments on term loan	(12,000)	(4,909)
Net cash provided by financing activities	63,190	14,129
Effect of exchange rates on cash and equivalents	(396)	(70)
Net increase (decrease) in cash and cash equivalents	(16,805)	10,789
Cash and cash equivalents - beginning of period	30,078	19,719
Cash and cash equivalents - end of period	13,273	30,508
Supplemental disclosures of other cash flow information:
Cash paid for interest expense	1,777	560
Supplemental disclosures of non-cash investing and financing information:
Purchase of property and equipment included in accounts payable	159	$ 347
Fair value of warrants issued in connection with term loan	4,799
Echelon Corporation [Member]
Cash flows from investing activities:
Acquisition, net of cash acquired	(28,836)
S3 Asic Semiconductors Limited [Member]
Cash flows from investing activities:
Acquisition, net of cash acquired	$ (34,616)

Organization and Summary of Sig

Organization and Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Summary of Significant Accounting Policies	Note 1. Organization and Summary of Significant Accounting Policies. Organization and Nature of Operations. Adesto Technologies Corporation (together with its subsidiaries; “Adesto”, “we”, “our”, “us” or the “Company”) was incorporated in the state of California in January 2006 and reincorporated in Delaware in October 2015. We are a leading provider of innovative, application-specific semiconductor and systems for the Internet of Things era. Our corporate headquarters are located in Santa Clara, California. On May 9, 2018 we acquired 100% of the issued capital of S3 Asic Semiconductors Limited and on September 14, 2018 we acquired 100% of the issued capital of Echelon Corporation. Our financial results include the operating results of those entities from the date of acquisition. Basis of Presentation. The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) for interim financial information and with the instructions to Form 10‑Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP to complete annual consolidated financial statements. In the opinion of our management, all adjustments (consisting of normal recurring adjustments) considered necessary to present fairly the financial position of the Company and its results of operations and cash flows for the interim periods presented have been included. Operating results for the nine months ended September 30, 2018 are not necessarily indicative of the results that may be expected for the year ending December 31, 2018, for any other interim period or for any other future year. The condensed consolidated balance sheet as of December 31, 2017 was derived from the audited consolidated financial statements as of that date, but does not include all of the disclosures required by U.S. GAAP. The accompanying condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto contained in the Company’s Annual Report on Form 10‑K for the year ended December 31, 2017, filed with the Securities and Exchange Commission on March 13, 2018. The condensed consolidated financial statements include the results of our operations, and the operations of our wholly owned subsidiaries. All intercompany balances and transactions have been eliminated. There have been no material changes to our significant accounting policies described in Note 1, Organization and Summary of Significant Accounting Policies, in Notes to Consolidated Financial Statements in Item 8 of Part II of our Annual Report on Form 10‑K for the year ended December 31, 2017 that have had a material impact on our condensed consolidated financial statements and related notes, except as described below. Recent Accounting Pronouncements. In August 2018, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2018-13, Fair Value Measurement Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement. As part of the FASB's disclosure framework project, it has eliminated, amended and added disclosure requirements for fair value measurements. Entities will no longer be required to disclose the amount of, and reasons for, transfers between Level 1 and Level 2 of the fair value hierarchy, the policy of timing of transfers between levels of the fair value hierarchy and the valuation processes for Level 3 fair value measurements. Public companies will be required to disclose the range and weighted average used to develop significant unobservable inputs for Level 3 fair value measurements. This ASU is effective for public entities for annual and interim periods beginning after December 15, 2019. Early adoption is permitted as of the beginning of any interim or annual reporting period. This ASU will have an impact on the Company's disclosures. In June 2018, FASB issued ASU No. 2018-07, Compensation—Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting. ASU 2018-07 applies to all entities that enter into share-based payment transactions for acquiring goods and services from nonemployees. The amendments in ASU 2018-07 expand the scope of Topic 718, Compensation - Stock Compensation, to include share-based payments transactions to nonemployees. Changes to the accounting for nonemployee awards as a result of ASU 2018-07 include: 1) equity-classified nonemployee share-based payment awards are measured at the grant date, instead of the previous requirement to remeasure the awards through the performance completion date, 2) for awards with performance conditions, compensation cost is recognized when the achievement of the performance condition is probable, rather than upon achievement, and 3) the current requirement to reassess the classification (equity or liability) for nonemployee awards upon vesting is eliminated. ASU 2018-07 clarifies that Topic 718 does not apply to financing transactions or awards granted to customers as part of a contract accounted for under Topic 606, Revenue from Contracts with Customers. The amendments in ASU 2018-07 are effective for public business entities for fiscal years beginning after December 15, 2018, and interim periods within that fiscal year. An entity should only remeasure liability-classified awards that have not been settled by the date of adoption and equity-classified awards for which the measurement date has not been established through a cumulative-effect adjustment to retained earnings as of the beginning of the fiscal year of adoption. The Company expects that the adoption will not have a material impact on its consolidated financial statements. In February 2018, FASB issued ASU No. 2018-02, Income Statement—Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. This ASU allows a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act. This ASU is effective for fiscal years beginning after December 15, 2018 and interim periods within those fiscal years. The Company expects that the adoption will not have a material impact on its consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-04, Intangibles—Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment. This ASU eliminates Step 2 from the goodwill impairment test. Instead, an entity should recognize an impairment charge for the amount by which the carrying value exceeds the reporting unit’s fair value, not to exceed the total amount of goodwill allocated to that reporting unit. This ASU is effective for annual or any interim goodwill impairment tests in fiscal years beginning after December 15, 2019. The Company is currently evaluating the effect of the adoption of this ASU, but anticipates that the adoption will not have a material impact on its consolidated financial statements. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. This ASU requires instruments measured at amortized cost to be presented at the net amount expected to be collected. Entities are also required to record allowances for available-for-sale debt securities rather than reduce the carrying amount. This ASU is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. The Company expects that the adoption will not have a material impact on its consolidated financial statements. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). The core principle of Topic 842 is that a lessee should recognize the assets and liabilities that arise from leases. For operating leases, a lessee is required to recognize a right-of-use asset and a lease liability, initially measured at the present value of the lease payments, in the statement of financial position. This ASU is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The Company is evaluating the effect that the adoption of this ASU will have on its consolidated financial statements. The Company currently expects that most of its operating lease commitments will be subject to the new standard and recognized as right-of-use assets and operating lease liabilities upon the adoption of ASU 2016-02, which will increase the total assets and total liabilities that it reports relative to such amounts prior to adoption. Recently Adopted Accounting Pronouncements. Adoption of ASC 606: In May 2014, the FASB issued an ASU on revenue from contracts with customers, ASU No. 2014-09, Revenue from Contracts with Customers (“Topic 606”). This standard update outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers. The guidance is effective for annual reporting periods including interim reporting reports beginning after December 15, 2017. Collectively, we refer to Topic 606, its related amendments and Subtopic 340-40 as the “new standard”. On January 1, 2018, we adopted the new standard using the modified retrospective method applied to all contracts that are not completed contracts at the date of initial application (i.e., January 1, 2018). Results for reporting periods after January 1, 2018 are presented under the new standard, while prior period amounts are not adjusted and continue to be reported in accordance with our historic accounting. There was no impact on the opening accumulated deficit as of January 1, 2018 due to the adoption of the new standard. We reclassified the allowance for ship from stock and debits (“SSDs”), price protection, rights of return and other activities to current liabilities presented as "Price adjustments and other revenue reserves" from the allowance for accounts receivable due to the adoption of the new standard. We recorded a cumulative effect adjustment to our January 1, 2018 condensed consolidated balance sheet for the impact of the reclassification of the allowance for SSDs, price protection, rights of return and other activities to current liabilities presented as “Price adjustments and other revenue reserves”. The cumulative effect of the changes made to our January 1, 2018 condensed consolidated balance sheet for the adoption of the new revenue standard were as follows (in thousands): Balance as of Adjustments Balance as of December 31, Due to January 1, 2017 ASC 606 2018 Accounts receivable, net $ 8,668 $ 3,832 $ 12,500 Price adjustments and other revenue reserves $ — $ (3,832) $ (3,832) In accordance with the new standard requirements, the disclosure of the impact of adoption on select condensed consolidated balance sheet line items was as follows (in thousands): As of September 30, 2018 As Balances without Effect of Reported ASC 606 Change Accounts receivable, net $ 24,706 $ 19,504 $ (5,202) Price adjustments and other revenue reserves $ 5,202 $ — $ 5,202 Revenue Recognition. Revenue is recognized when control of the promised goods or services is transferred to customers, in an amount that reflects the consideration we expect to be entitled to in exchange for those goods or services. Sales of products with alternative use account for the majority of our revenue and are recognized at a point in time, the timing of such recognition remained the same under Topic 606. Taxes assessed by a governmental authority that are both imposed on and concurrent with a specific revenue-producing transaction, that are collected by us from a customer and deposited with the relevant government authority, are excluded from revenue. Our revenue arrangements do not contain significant financing components. Revenue is recognized over a period of time when it is assessed that performance obligations are satisfied over a period rather than at a point in time. When any of the following criteria is fulfilled, revenue is recognized over a period of time: (a) The customer simultaneously receives and consumes the benefits provided by the performance as Adesto performs. (b) Adesto’s performance creates or enhances an asset (for example, work in process) that the customer controls as the asset is created or enhanced. (c) Adesto’s performance does not create an asset with an alternative use, and Adesto has an enforceable right to payment for performance completed to date. If revenue is recognized over a period of time, we would then select an appropriate method for measuring progress toward complete satisfaction of the performance obligation, usually costs incurred to date relative to the total expected costs to the satisfaction of that performance obligation. Typically, our revenue is recognized at a point in time. Sales to certain distributors are made under arrangements which provide the distributors with price adjustments, price protection, stock rotation and other allowances under certain circumstances. These adjustments and allowances are accounted for as variable consideration. We estimate these amounts based on the expected amount to be provided to customers and reduce revenue recognized. We believe that there will not be significant changes to our estimates of variable consideration. If a customer pays consideration, or Adesto has a right to an amount of consideration that is unconditional before we transfer a good or service to the customer, those amounts are classified as deferred income/ advances received from customers which are included in other current liabilities or other long-term liabilities when the payment is made or it is due, whichever is earlier. If the arrangement includes variable contingent consideration, we recognize revenue over time if we can reasonably measure its progress, or we are capable of providing reliable information that would be required to apply an appropriate method of measuring progress. To date, we have not had any arrangements incorporating contingent consideration. Practical Expedients and Elections. Sales commissions are owed and are recorded at the time of sell through of our products to end customers. These costs are recorded within sales and marketing expenses. We do not disclose the value of unsatisfied performance obligations for (i) contracts with an original expected length of one year or less and (ii) contracts for which we recognize revenue at the amount to which we have the right to invoice for services performed. We have elected to account for shipping and handling costs as fulfillment costs after the customer obtains control of the goods. These costs are recorded in cost of revenue. Reclassifications. Certain reclassifications have been made to prior periods’ condensed consolidated financial statements to conform to the current period presentation. These reclassifications did not result in any change in previously reported total assets, stockholders’ equity or net loss. Use of Estimates. The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates, judgments and assumptions that affect the reported amount of assets, liabilities, revenue and expenses and related disclosures of contingent assets and liabilities. On an on-going basis, we evaluate those estimates, including those related to allowances for doubtful accounts, price adjustments and other revenue reserves, warranty accrual, inventory write-downs, valuation of long-lived assets, including property and equipment and identifiable intangible assets and goodwill, loss on purchase commitments, valuation of deferred taxes and contingencies. In addition, we use assumptions when employing the Black-Scholes option-pricing model to calculate the fair value of stock options granted and Monte Carlo simulation techniques to value certain restricted stock units with market-based vesting conditions. We base our estimates of the carrying value of certain assets and liabilities on historical experience and on various other assumptions that are believed to be reasonable under the circumstances, when these carrying values are not readily available from other sources. Actual results could differ from these estimates. Product Warranty. Our products are sold with a limited warranty for a period of one year, warranting that the product conforms to specifications and is free from material defects in design, materials and workmanship. To date, we have had insignificant returns of any defective production parts. During the year ended December 31, 2015, we recorded $250,000 for a specific potential warranty claim. During the years ended December 31, 2017 and 2016, $185,000 and $41,000, respectively, has been incurred relating to this potential warranty claim and during the year ended December 31, 2017 we recorded $27,000 for an additional potential warranty claim. As of September 30, 2018 and December 31, 2017, the warranty accrual was $51,000 and is included in accrued expenses and other current liabilities on the condensed consolidated balance sheets. Foreign Currency Translation. The functional currency of our foreign subsidiaries is the local currency. In consolidation, we translate assets and liabilities at exchange rates in effect at the consolidated balance sheet date. We translate revenue and expense accounts at the average exchange rates during the period in which the transaction takes place. Net losses from foreign currency translation of assets and liabilities were $ 148,000 and $20,000 for the three months ended September 30, 2018 and 2017, respectively, and $65,000 and $71,000 for the nine months ended September 30, 2018 and 2017, respectively, and are included in the cumulative translation adjustment component of accumulated other comprehensive loss, net of tax, a component of stockholders’ equity. Net gains and losses arising from transactions denominated in currencies other than the functional currency were a gain of $9,000 and a loss of $7,000 for the three months ended September 30, 2018 and 2017, respectively, and a loss of $1,000 and a gain of $1,000 for the nine months ended September 30, 2018 and 2017, respectively, and are included in other income (expense), net in the condensed consolidated statements of operations. Concentration of Risk. Our products are primarily manufactured, assembled and tested by third-party foundries and other contractors in Asia and we are heavily dependent on a single foundry in Taiwan for the manufacture of wafers and a single contractor in the Philippines for assembly and testing of our products. We do not have long-term agreements with either of these suppliers. A significant disruption in the operations of these parties would adversely impact the production of our products for a substantial period of time, which could have a material adverse effect on our business, financial condition, operating results and cash flows. Financial instruments that potentially subject us to significant concentrations of credit risk consist principally of cash and cash equivalents, investments and accounts receivables. We place substantially all of our cash and cash equivalents and investments on deposit with a reputable, high credit quality financial institution in the United States of America. We believe that the bank that holds substantially all of our cash and cash equivalents and investments is financially sound and, accordingly, subject to minimal credit risk. Deposits held with the bank may exceed the amount of insurance provided on such deposits. We generally do not require collateral or other security in support of accounts receivable. We periodically review the need for an allowance for doubtful accounts by considering factors such as historical experience, credit quality, the age of the accounts receivable balances and current economic conditions that may affect a customer’s ability to pay. The allowance for doubtful accounts as of September 30, 2018 and December 31, 2017 was $30,000 and zero, respectively. Customer concentrations as a percentage of revenue, net were as follows: Three Months Ended Nine Months Ended September 30, September 30, 2018 2017 2018 2017 Customer A 20 % 13 % 21 % 16 % Customer B * 12 % * 10 % Customer C * 13 % * 12 % * Customer concentrations as a percentage of gross accounts receivable were as follows: September 30, December 31, 2018 2017 Customer A 22 % 31 % Customer B 13 % * *

Acquisition

Acquisition	9 Months Ended
	Sep. 30, 2018
Business Combinations [Abstract]
Acquisition	Note 2. Acquisitions. Echelon Corporation On September 14, 2018, we acquired 100% of the issued capital of Echelon Corporation, a Delaware corporation (“Echelon”), pursuant to the terms of an Agreement and Plan of Merger (the “Merger Agreement”) dated as of June 28, 2018. The purchase price was approximately $44.1 million paid in cash. The assets and liabilities of Echelon were recorded in our condensed consolidated balance sheet as of the acquisition date, at their respective fair values. Fair value is estimated based on one or a combination of income, cost and/or market approaches, as determined based on the nature of the asset or liability, and the level of inputs available. With respect to assets and liabilities, the determination of fair value requires management to make subjective judgments as to projections of future operating performance, the appropriate discount rate to apply, long-term growth rates, and other factors, which affect the amounts recorded in the purchase price allocation. The excess of the consideration transferred over the fair value of the identifiable assets, net of liabilities, is recorded as goodwill, which is indicative of the expected continued growth and development of Echelon. The purchase price allocation that follows is based on these estimated fair values of assets acquired and liabilities assumed. We will continue to evaluate certain assets, liabilities and tax estimates that are subject to change within the measurement period (up to one year from the acquisition date). The following table summarizes the fair values of assets acquired and liabilities assumed (in thousands): Cash $ 15,270 Short term investments 1,274 Accounts receivable 3,020 Inventories 5,710 Other current assets 2,845 Property and equipment, net 614 Intangible assets 17,690 Goodwill 4,266 Other non-current assets 252 Accounts payable (3,630) Other current liabilities (2,642) Other non-current liabilities (222) Deferred tax liability (341) Fair value net assets acquired $ 44,106 Intangible assets reflect the following: Fair Value Useful Customer relationships $ 6,520 Developed technology 10,670 Trademarks 500 Total acquired intangible assets $ 17,690 Pro forma financial information The following table presents the unaudited pro forma financial information for the combined entity of Adesto and Echelon for the three and nine month periods ended September 30, 2018, as if the acquisition had occurred at the beginning of the periods presented after giving effect to certain purchase accounting adjustments. Echelon was acquired on September 14, 2018. Three Months Ended Nine Months Ended September 30, September 30, 2018 2017 2018 2017 (in thousands except per share amounts) Net revenue $ 27,541 $ 23,157 $ 76,780 $ 63,916 Net loss $ (8,124) $ (1,842) $ (17,087) $ (8,737) Basic and diluted net loss per share $ (0.29) $ (0.06) $ (0.72) $ (0.34) S3 Asic Semiconductors Limited On May 9, 2018, we acquired 100% of the issued capital of S3 Asic Semiconductors Limited, a private company limited by shares and incorporated in Ireland (“S3”), pursuant to the Share Purchase Agreement dated May 9, 2018 (the “Agreement”). S3 is headquartered in Ireland and its subsidiaries are in the United States, Portugal and the Czech Republic. S3 and its subsidiaries are engaged in the business of providing advanced mixed signal semiconductor devices and intellectual property to customers in the industrial and communications markets. The aggregate consideration was approximately $35.0 million in cash and contingent consideration in the form of a $15.0 million earn-out. The earn-out is based on achievement of certain milestones through 2019, including minimum total revenue targets, revenue derived from sales of semiconductor devices and new customer engagements with minimum value thresholds. The assets and liabilities of S3 were recorded in our condensed consolidated balance sheet as of the acquisition date, at their respective fair values. Fair value is estimated based on one or a combination of income, cost and/or market approaches, as determined based on the nature of the asset or liability, and the level of inputs available. With respect to assets and liabilities, the determination of fair value requires management to make subjective judgments as to projections of future operating performance, the appropriate discount rate to apply, long-term growth rates, and other factors, which affect the amounts recorded in the purchase price allocation. The excess of the consideration transferred over the fair value of the identifiable assets, net of liabilities, is recorded as goodwill, which is indicative of the expected continued growth and development of S3. The purchase price allocation that follows is based on these estimated fair values of assets acquired and liabilities assumed. We will continue to evaluate certain assets, liabilities and tax estimates that are subject to change within the measurement period (up to one year from the acquisition date). The following table summarizes the fair values of assets acquired and liabilities assumed (in thousands): Cash $ 267 Accounts receivable 192 Other current assets 883 Property and equipment, net 191 Intangible assets 15,340 Goodwill 34,352 Accounts payable (37) Deferred revenue (129) Earn-out liability, current (10,218) Other current liabilities (761) Deferred tax liability (1,918) Earn-out liability, non-current (3,279) Fair value of net assets acquired $ 34,883 Intangible assets reflect the following: Fair Value Useful Customer relationships $ 12,880 7 Contract backlog 210 0.5 Developed technology 1,080 5 Non-compete agreements 380 2 Trademarks 790 12 Total $ 15,340

Balance Sheet Components

Balance Sheet Components	9 Months Ended
	Sep. 30, 2018
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Components	Note 3. Balance Sheet Components. Accounts Receivable, Net. Accounts receivable, net consisted of the following (in thousands): September 30, December 31, 2018 2017 Accounts receivable $ 24,736 $ 12,500 Allowance for SSDs, price protection, rights of return and other activities — (3,832) Allowance for doubtful accounts (30) — Total accounts receivable, net $ 24,706 $ 8,668 Inventories. Inventories consisted of the following (in thousands): September 30, December 31, 2018 2017 Raw materials $ 2,298 $ 2,213 Work-in-process 8,430 2,408 Finished goods 6,813 1,193 Total inventories $ 17,541 $ 5,814 For the three months ended September 30, 2018, we recorded a write-down of $16,000 related to excess inventory. For the three months ended September 30, 2017, we realized a benefit of $0. 4 million from the sales of previously reserved products. For the nine months ended September 30, 2018 and 2017, we realized a benefit of $0.9 million and $1.0 million, respectively, from the sales of previously reserved products. Inventory write-downs are primarily associated with products built in excess of customer demand which resulted in excess inventory levels, legacy products for which no demand exists and lower of cost or net realizable value write-downs associated with products for which costs exceeded net realizable value. Property and Equipment, Net. Property and equipment, net consisted of the following (in thousands): September 30, December 31, 2018 2017 Machinery and equipment $ 14,936 $ 9,457 Leasehold improvements 4,463 4,252 Computer software 3,765 675 TowerJazz license 350 350 Furniture and fixtures 246 83 Construction in progress 1,301 1,301 Property and equipment, at cost 25,061 16,118 Accumulated depreciation and amortization (16,332) (8,935) Property and equipment, net $ 8,729 $ 7,183 The Company incurs costs for the fabrication of masks used by its foundry partners to manufacture its products. Beginning the first fiscal quarter of 2017, the Company capitalizes mask costs that are expected to be utilized in production manufacturing as the Company’s product development process has become more predictable and thus supports capitalization of the mask. The capitalized mask costs begin depreciating to cost of revenue once the products go into production. Depreciation is computed using the straight-line method over a three year period which is the expected useful life of the mask. Previously mask sets were expensed to research and development. Depreciation and amortization expense of property and equipment for the three and nine months ended September 30, 2018 was $0. 6 million and $1.7 million, respectively. Depreciation and amortization expense of property and equipment for the three and nine months ended September 30, 2017 was $0. 4 million and $ 1.0 million, respectively Accrued Expenses and Other Current Liabilities. Accrued expenses and other current liabilities consisted of the following (in thousands): September 30, December 31, 2018 2017 Accrued sales commission payable $ 318 $ 310 Accrued manufacturing expenses 537 265 Deferred rent, current portion 527 422 Liabilities to certain customers 812 468 Deferred revenue, current portion 1,454 262 Accrued professional services 1,903 94 Other accrued liabilities 1,418 538 Total accrued expenses and other current liabilities $ 6,969 $ 2,359

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	Note 4. Fair Value Measurements. Fair value is defined as the exchange price that would be received from selling an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. We measure financial assets and liabilities at fair value at each reporting period using a fair value hierarchy which requires us to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. A financial instrument’s classification within the fair value hierarchy is based upon the lowest level of input that is significant to the fair value measurement. Three levels of inputs may be used to measure fair value: Level 1. Quoted prices in active markets for identical assets or liabilities. Level 2. Quoted prices for similar assets and liabilities in active markets or inputs other than quoted prices which are observable for the assets or liabilities, either directly or indirectly through market corroboration, for substantially the full term of the financial instruments. Level 3. Unobservable inputs which are supported by little or no market activity and which are significant to the fair value of the assets or liabilities. Financial assets measured at fair value on a recurring basis were as follows: Fair Value Measurement at Reporting Date Using Significant Quoted Prices in Other Significant Active Markets Observable Unobservable for Identical Inputs Inputs Assets (Level 1) (Level 2) (Level 3) Total (in thousands) As of September 30, 2018 Assets: Money market funds $ 6 $ — $ — $ 6 U.S. government securities — 1,275 — 1,275 $ 6 $ 1,275 $ — $ 1,281 As of December 31, 2017 Assets: Money market funds $ 11,501 $ — $ — $ 11,501 As of September 30, 2018 and December 31, 2017, we had no financial liabilities measured at fair value on a recurring basis. The Company’s available-for-sale securities consist of U.S. government securities with a minimum and weighted average credit rating of A-1+. The Company values these securities based on pricing from pricing vendors, who may use quoted prices in active markets for identical assets (Level 1 inputs) or inputs other than quoted prices that are observable either directly or indirectly (Level 2 inputs) in determining fair value. However, the Company classifies all of its fixed income available-for-sale securities as having Level 2 inputs. The valuation techniques used to measure the fair value of the Company’s financial instruments having Level 2 inputs were derived from non-binding market consensus prices that are corroborated by observable market data, quoted market prices for similar instruments, or pricing models, such as discounted cash flow techniques. The Company's procedures include controls to ensure that appropriate fair values are recorded by comparing prices obtained from a third party independent source. The Company’s available-for-sale securities had contractual maturities of six months and an average remaining term to maturity of three months. The amortized cost basis, aggregate fair value, and gross unrealized holding gains and losses of the Company’s short-term investments by major security type were as follows (in thousands): Aggregate Unrealized Unrealized Amortized Cost Fair Value Holding Gain Holding Losses As of September 30, 2018 U.S. government securities $ 1,275 $ 1,275 $ — $ — Market values were determined for each individual security in the investment portfolio. The Company reviews its investments on a regular basis to evaluate whether or not any have experienced an other-than-temporary decline in fair value.

Intangible Assets, net

Intangible Assets, net	9 Months Ended
	Sep. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets, net	Note 5. Intangible Assets, net. In 2012, in connection with our purchase of the serial flash memory product line assets from Atmel Corporation, we recorded $16.4 million of intangible assets. In connection with the acquisition of S3 (Note 2), we recorded $15.3 million of intangible assets. In connection with the acquisition of Echelon (Note 2), we recorded $17.7 million of intangible assets. Intangible assets, net were as follows (in thousands): September 30, 2018 Estimated Useful Gross Carrying Accumulated Net Carrying Developed technology 10 $ 4,282 $ 2,570 $ 1,712 Developed technology 5 1,080 85 995 Developed technology 4 10,670 119 10,551 Customer relationships 12 9,011 4,505 4,506 Customer relationships 7 19,400 763 18,637 Customer backlog 1 2,779 2,779 — Contract backlog 0.5 210 165 45 Non-compete agreement 5 282 282 — Non-compete agreement 2 380 74 306 Trademarks 8 500 3 497 Trademarks 12 790 26 764 Total intangible assets subject to amortization $ 49,384 $ 11,371 $ 38,013 December 31, 2017 Estimated Useful Gross Carrying Accumulated Net Carrying Developed technology 10 $ 4,282 $ 2,249 $ 2,033 Customer relationships 12 9,011 3,942 5,069 Customer backlog 1 2,779 2,779 — Non-compete agreement 5 282 282 — Total intangible assets subject to amortization $ 16,354 $ 9,252 $ 7,102 We recorded amortization expense related to the acquisition-related intangible assets as follows (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2018 2017 2018 2017 Operating expense category: Research and development $ 323 $ 121 $ 567 $ 364 Sales and marketing 763 188 1,472 563 General and administrative 52 — 80 — Total $ 1,138 $ 309 $ 2,119 $ 927 The estimated future amortization expense of acquisition-related intangible assets subject to amortization after September 30, 2018 is as follows (in thousands): Year Ended December 31, 2018 (remaining 3 months) $ 1,833 2019 7,152 2020 7,030 2021 6,962 2022 6,070 Thereafter 8,966 Total $ 38,013

Investment in Unconsolidated Af

Investment in Unconsolidated Affiliates	9 Months Ended
	Sep. 30, 2018
Investments, All Other Investments [Abstract]
Investment in Unconsolidated Affiliates	Note 6. Investment in Unconsolidated Affiliates. During 2017 and 2016, we made investments in Semitech Semiconductor Pty. Ltd., an Australian corporation (“Semitech”), as part of a license and development agreement dated April 16, 2016. Semitech has developed Narrowband-Power Line Communications (“N-PLC”) products and market knowledge in the N-PLC devices space and plans to sell its products into the smart grid, solar, smart lighting and industrial space. Investments during 2016 through June 14, 2017 were recorded as notes receivable. On June 15, 2017, $0.4 million of notes receivable and accrued interest were converted into 233,335 shares of preferred stock in Semitech. In June 2018, we converted $0.5 million of notes receivable and accrued interest into 312,076 shares of preferred stock in Semitech. This investment is recorded at cost in other non-current assets on the condensed consolidated balance sheets as of September 30, 2018 and December 31, 2017. As of September 30, 2018 and December 31, 2017, we held investments in notes receivable in Semitech in the amount of $0.1 million and $0.2 million, respectively, which were classified in other non-current assets on the condensed consolidated balance sheets.

Borrowings

Borrowings	9 Months Ended
	Sep. 30, 2018
Debt Disclosure [Abstract]
Borrowings	Note 7. Borrowings. Western Alliance Bank Term Loan. The Company was a party to that certain Business Financing Agreement dated July 7, 2016 and that certain Second Business Financing Modification Agreement, dated September 29, 2017, by and between Western Alliance Bank and the Company (“Credit Facility”). The Credit Facility provided for (i) a term loan of up to $18.0 million (the “Term Loan”) and (ii) a revolving credit line advance (the “Line of Credit”) in the aggregate amount of the lower of (x) $5.0 million and (y) 80% of certain of the Company’s receivables. The Term Loan bore interest at a rate per annum equal to the greater of the prime rate or 3.5%, plus 0.75% and was scheduled to mature in June 2019. The Line of Credit bore interest at a rate per annum equal to the greater of the prime rate or 3.5% plus 0.50%), and was scheduled to mature in July 2018. We made interest-only payments on the Term Loan from July 2016 through September 2016 and began making interest payments and principal payments in 33 equal monthly installments starting October 2016. Prior to the Amendment, the Credit Facility provided that any indebtedness we incurred thereunder was collateralized by substantially all assets of the Company and any domestic subsidiaries, subject to certain customary exceptions. We paid a facility fee of $150,000 as well as a $25,000 diligence fee upon entry into the Credit Facility and an additional $10,000 on July 7, 2017. Additional fees of $25,000 were incurred in connection with the amendment. These fees were recorded as a debt discount and were amortized over the life of the agreement. Borrowings of $12.0 million under this facility were repaid in full in May 2018. In connection with the repayment of this facility, the remaining unamortized debt discount of $66,000 was recorded as interest expense in the condensed consolidated statements of operations. Cortland Capital Market Services LLC Term Loan. One May 8, 2018, we entered into a credit agreement with Cortland Capital Market Services LLC (“Cortland”) (“Credit Agreement”). The Credit Agreement provides for a 1 st lien senior secured term loan of $35.0 million (“Term Loan”). The Term Loan bears interest at a rate per annum equal to the sum of the Libor Rate (2.4375% on September 30, 2018) plus 8.75% and is payable in consecutive quarterly installments starting December 31, 2018. The Term Loan is scheduled to mature on May 8, 2022. The Credit Agreement provided that any indebtedness we incurred thereunder was collateralized by substantially all assets of the Company and any domestic subsidiaries, subject to certain customary exceptions. The Credit Agreement contains customary representations and warranties and affirmative and negative covenants, including maximum consolidated leverage ratios and minimum liquidity. Upon an occurrence of an event of default, under the Credit Facility we could be required to pay interest on all outstanding obligations under the agreement at a rate of 2% above the otherwise applicable interest rate, and the lender may accelerate our obligations under the agreement. In connection with the Credit Agreement, Cortland received a warrant to purchase 850,000 shares of common stock at an exercise price of $8.30 and a term of six years. In addition, we paid financing costs of $1.4 million. The financing costs and the value of the warrant, $4.8 million, were recorded as a debt discount and are being amortized over the life of the Credit Agreement. Amortization of debt discount was $0.4 million and $0.7 million for the three and nine months ended in September 30, 2018, respectively. Outstanding borrowings consisted of the following (in thousands): September 30, December 31, 2018 2017 Term loan, current $ — $ 926 Term loan, non-current 29,433 10,908 Line of credit — 1,500 Total $ 29,433 $ 13,334 Future repayments on outstanding borrowings (excluding unamortized discount of $5.6 million as of September 30, 2018) are as follows (in thousands): Year Ended December 31, 2018 (remaining 3 months) $ 292 2019 1,750 2020 1,750 2021 1,750 2022 29,458 $ 35,000 Interest expense incurred under our borrowings was $1. 1 million and $2.4 million for the three and nine months ended September 30, 2018, respectively. Interest expense incurred under our borrowings was $ 0.2 million and $0. 6 million for the three and nine months ended September 30, 2017, respectively.

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2018
Segment Reporting [Abstract]
Segment Information	Note 8. Segment Information. We operate in one business segment, application-specific, semiconductors and systems. Our chief decision-maker, the President and Chief Executive Officer, evaluates our performance based on company-wide consolidated results. Revenue is evaluated based on product category and by geographic region. All of our revenue results from contracts with customers; we have no additional sources of revenue. Product revenue from customers is disaggregated based on the geographic region to which the product is delivered. Revenue by geographic region was as follows (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2018 2017 2018 2017 United States $ 7,253 $ 3,331 $ 15,472 $ 8,853 Rest of Americas 583 58 868 189 Europe 5,087 2,044 11,708 6,054 Asia Pacific 8,865 9,729 27,078 24,540 Rest of world 139 77 286 322 Total $ 21,927 $ 15,239 $ 55,412 $ 39,958 Long-lived assets are attributed to the geographic region were they are located. Long-lived assets by geographic region were as follows (in thousands): September 30, December 31, 2018 2017 United States $ 5,511 $ 5,424 Asia Pacific 2,325 1,759 Europe 893 — Total property and equipment, net $ 8,729 $ 7,183

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 9. Commitments and Contingencies. Operating Leases. The Company leases office facilities under various non-cancelable operating lease agreements. Certain lease agreements contain free or escalating rent payment provisions. The Company recognizes rent expense under such leases on a straight-line basis over the term of the lease with the difference between the expense and the payments recorded as deferred rent on the consolidated balance sheets. Any reimbursements by the landlord for tenant improvements are considered lease incentives, the balance of which is recorded as a lease incentive obligation within deferred rent on the consolidated balance sheets, and amortized as a reduction of rent expense over the life of the lease. Lease renewal periods are considered on a lease-by-lease basis in determining the lease term. On November 2, 2015, the Company entered into a lease with Peterson Ridge LLC pursuant to which the Company leased a new headquarters facility, consisting of an aggregate of approximately 34,000 square feet of space in Santa Clara, California. The initial term of the lease commenced on November 2, 2015 and is scheduled to end on July 31, 2023 and may be extended, at the Company’s option, for an additional five-year period following the initial lease term. Pursuant to the lease, monthly base rental payments due under the lease were approximately $93,000 per month between August 1, 2016 and February 27, 2017, with annual increases of approximately 3% thereafter. The Company must also pay for certain other operating costs under the lease, including operating expenses, taxes, assessments, insurance, utilities, securities and property management fees. Peterson Ridge LLC is obligated to reimburse the Company for up to approximately $2.5 million of the Company’s out-of-pocket costs associated with any tenant improvements, as defined in the lease. The Company was reimbursed for this amount during the year ended December 31, 2016. As of September 30, 2018 and December 31, 2017, the Company recorded a lease incentive obligation of $1.7 million and $2.0 million, respectively, in deferred rent on the condensed consolidated balance sheets. Rent expense under operating leases was $0. 5 million and $1.2 million for the three and nine months ended September 30, 2018, respectively. Rent expense under operating leases was $0.3 million and $0.8 million for the three and nine months ended September 30, 2017, respectively 3 Total 2018 2019 2020 2021 2022 Thereafter (in thousands) Operating leases $ 7,994 $ 674 $ 2,148 $ 1,588 $ 1,466 $ 1,325 $ 793 Purchase Commitments. As of September 30, 2018, we had purchase commitments with our third-party foundries of $3.3 million, $0.1 million for a licensing and development agreement, and $0.4 million in conjunction with an agreement with TowerJazz Panasonic Semiconductor Company all due within one year. Litigation. We are 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. We accrue amounts that we believe are adequate to address any liabilities related to legal proceedings and other loss contingencies that we believe will result in a probable loss that is reasonably estimable. Indemnification. During the normal course of business, we may make certain indemnities, commitments and guarantees which may include intellectual property indemnities to certain of our customers in connection with the sales of our products and indemnities for liabilities associated with the infringement of other parties’ technology based upon our products. Our exposure under these indemnification provisions is generally limited to the total amount paid by a customer under the agreement. However, certain agreements include indemnification provisions that could potentially expose us to losses in excess of the amount received under the agreement. In addition, we indemnify our officers, directors and certain key employees while they are serving in good faith in such capacities. We have not recorded any liability for these indemnities, commitments and guarantees in the accompanying condensed consolidated balance sheets. Where necessary, we accrue for losses for any known contingent liabilities, including those that may arise from indemnification provisions, when future payment is probable.

Common Stock, Common Stock Warr

Common Stock, Common Stock Warrants and Stock Option Plan	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Common Stock, Common Stock Warrants and Stock Option Plan	Note 10. Common Stock, Common Stock Warrants and Stock Option Plan. Common Stock. We are authorized to issue 100,000,000 shares of common stock with $0.0001 par value per share as of September 30, 2018 and December 31, 2017. Each holder of common stock is entitled to one vote per share. As of September 30, 2018, no dividends have been declared by the Board of Directors, however, the holders of common stock are also entitled to receive dividends, when and if declared by our Board of Directors. We completed a follow-on offering of our common stock in June 2017. We sold 5,000,000 shares, including 625,000 shares upon exercise of the underwriters’ option to purchase additional shares. The shares were sold at a public offering price of $4.00 per share for net proceeds of $18.4 million to us, after deducting underwriting discounts, commissions and offering expenses. We completed another follow-on offering of our common stock in July 2018. We sold 7,705,000 shares, including 1,005,000 shares upon exercise of the underwriters’ option to purchase additional shares. The shares were sold at a public offering price of $6.00 per share for net proceeds of $42.7 million to us, after deducting underwriting discounts, commissions and offering expenses. Common Stock Reserved for Future Issuance. As of September 30, 2018 and December 31, 2017, we had reserved shares of common stock for future issuances as follows: September 30, December 31, 2018 2017 Warrants to purchase common stock 1,239,423 389,423 Stock option plan: Options outstanding 1,844,030 1,560,453 Restricted stock units outstanding 1,074,193 509,894 Shares available for future grants 289,258 580,827 Shares available for ESPP 362,938 275,587 Total 4,809,842 3,316,184 Common Stock Warrants. In connection with the Credit Agreement (Note 7), the Company issued Cortland a warrant to purchase 850,000 shares of common stock at an exercise price of $8.30 per share with a term of six years. The grant date fair value of the warrant was approximately $4.8 million which was recorded as a debt discount and is being amortized over the life of the Credit Agreement. The fair value of the warrant was determined using the Black-Scholes Model based on the following assumptions: common stock price on date of grant of $8.70, dividend yield of 0%, volatility of 69.73%, a risk-free interest rate 2.87% and a term of 6 years. The following common stock warrants were outstanding: As of September 30, 2018 Total amount of securities issuable under the outstanding warrants Exercise Price Issuance Date Expiration Date $ 30.35 2012-2013 $ 2.38 2014-2015 2022-2024 $ 8.30 $ 8.11 As of December 31, 2017 Total amount of securities issuable under the outstanding warrants Exercise Price Issuance Date Expiration Date $ 30.35 2012-2013 $ 2.38 2014-2015 2022-2024 $ 7.71 Common stock warrants are exercisable at the option of the holder any time after the date of issuance into shares of our common stock. During 2017, common stock warrants with an aggregate 7,378 shares of issuable common stock expired and common stock warrants with an aggregate 14,713 shares of issuable common stock were cashless exercised resulting in the issuance of 10,223 shares of common stock. Employee Benefit Plans. 2007 Equity Incentive Plan. In 2007, our Board of Directors and shareholders approved the 2007 Equity Incentive Plan (the “2007 Plan”) under which 272,727 shares of common stock were reserved and available for the issuance of stock options and restricted stock to eligible participants. The 2007 Plan was subsequently amended to increase the number of shares of common stock reserved for issuance under the 2007 Plan to 787,878 and during the year ended December 31, 2015, the number of shares reserved for issuance under the 2007 Plan was increased to 2,651,515. Options and restricted stock awards were granted at a price per share not less than the 85% of the fair value at the date of grant or award, respectively. Restricted stock awarded to persons controlling more than 10% of our stock were granted at a price per share not less than the 100% of the fair value at the date of the award. Options that were granted to new employees generally vest over a four-year period with 25% vesting at the end of one year and the remaining to vest monthly thereafter, while options that were granted to existing employees generally vest over a four-year period. Options granted generally are exercisable up to 10 years from the date of grant. As of October 26, 2015, no shares were available for grant under the 2007 Plan and all outstanding options would continue to be governed and remain outstanding in accordance with their existing terms. In addition, any shares subject to outstanding awards under the 2007 Plan that are issuable upon the exercise of options that expire or become unexercisable for any reason without having been exercised in full will be available for future grant and issuance under the 2015 Plan (as defined below). 2015 Equity Incentive Plan. In September 2015, our Board of Directors adopted, and in October 2015 our stockholders approved, our 2015 Equity Incentive Plan. The 2015 Equity Incentive Plan became effective on the date immediately prior to the date of our initial public offering (“IPO”). As a result, 1,813,272 shares of common stock previously reserved but unissued under the 2007 Plan on the effective date of the 2015 Equity Incentive Plan became reserved for issuance under our 2015 Equity Incentive Plan, and we ceased granting awards under our 2007 Plan. The number of shares reserved for issuance under our 2015 Equity Incentive Plan will increase automatically on the first day of January of each of 2016 through 2025 by the number of shares equal to 4% of the total outstanding shares of our common stock as of the immediately preceding December 31. However, our Board of Directors may reduce the amount of the increase in any particular year. Our 2015 Equity Incentive Plan authorizes the award of stock options, restricted stock awards, stock appreciation rights, restricted stock units (“RSUs”), performance awards and stock bonuses. No person will be eligible to receive more than 2,000,000 shares in any calendar year under our 2015 Equity Incentive Plan other than a new employee of ours, who will be eligible to receive no more than 4,000,000 shares under the plan in the calendar year in which the employee commences employment. The aggregate number of shares of our common stock that may be subject to awards granted to any one non-employee director pursuant to the 2015 Equity Incentive Plan in any calendar year shall not exceed 300,000. Our 2015 Equity Incentive Plan provides that no more than 25,000,000 shares will be issued as incentive stock options. 2015 Employee Stock Purchase Plan. In September 2015, our Board of Directors adopted, and in October 2015 our stockholders approved, our 2015 Employee Stock Purchase Plan (“ESPP”). The 2015 Employee Stock Purchase Plan became effective on the date of our IPO. We reserved 150,000 shares of our common stock for issuance under our 2015 Employee Stock Purchase Plan. The number of shares reserved for issuance under our 2015 Employee Stock Purchase Plan will increase automatically on the first day of January following the first offering date by the number of shares equal to 1% of the total outstanding shares of our common stock as of the immediately preceding December 31 (rounded to the nearest whole share). However, our Board of Directors may reduce the amount of the increase in any particular year. The aggregate number of shares issued over the term of our 2015 Employee Stock Purchase Plan will not exceed 2,250,000 shares of our common stock. Under our 2015 Employee Stock Purchase Plan, eligible employees will be able to acquire shares of our common stock by accumulating funds through payroll deductions. Eligible employees will be able to select a rate of payroll deduction up to 15% of their base cash compensation. The purchase price for shares of our common stock purchased under our 2015 Employee Stock Purchase Plan will be 85% of the lesser of the fair market value of our common stock on (i) the first trading day of the applicable offering period and (ii) the last trading day of each purchase period in the applicable offering period. Except for the first offering period, each offering period will run for no more than nine months, with purchases occurring every nine months. The first offering period began upon the effective date of our IPO and was originally set to end on June 30, 2016. On May 25, 2016, the Board of Directors extended the initial offering period to July 31, 2016. Subsequent purchase periods will be 6 months in duration beginning on August 1, 2016. On July 29, 2016, we issued 68,392 shares of common stock in conjunction with the end date of the initial purchase window. During 2017, we issued 110,711 shares of common stock pursuant to the ESPP. On January 31, 2018 we issued 55,806 shares of common stock pursuant to the ESPP. On July 31, 2018 we issued 69,761 shares of common stock in conjunction with the end date of the latest purchase window. No participant will have the right to purchase shares of our common stock in an amount that has a fair market value greater than $25,000, determined as of the first day of the applicable purchase period, for each calendar year in which that right is outstanding. In addition, no participant will be permitted to purchase more than 2,500 shares during any one purchase period or a lesser amount as determined by our compensation committee. Our 2015 Employee Stock Purchase Plan will continue until the earlier to occur of its termination by our Board of Directors, the issuance of all shares reserved for issuance under it or the tenth anniversary of its effective date. A summary of stock option and RSUs (including performance-based RSU) activity under the 2007 Plan and the 2015 Equity Incentive Plan is as follows: Stock Options Weighted- Weighted- Average Average Remaining Aggregate Exercise Contractual Intrinsic Shares Price Term (Years) Value (aggregate intrinsic value in thousands) Outstanding as of December 31, 2015 796,356 2.49 6.5 $ 4,157 Granted 230,200 3.38 Exercised (13,112) 1.80 Canceled (21,549) 3.73 Outstanding as of December 31, 2016 991,895 2.68 6.3 $ 161 Granted 835,480 4.30 Exercised (230,123) 1.92 Canceled (36,799) 4.16 Outstanding as of December 31, 2017 1,560,453 3.63 7.6 $ 4,632 Granted 448,200 7.45 Exercised (108,222) 2.43 Canceled (56,401) 3.49 Outstanding as of September 30, 2018 1,844,030 $ 4.63 7.8 $ 3,397 Options vested and expected to vest as of September 30, 2018 1,750,842 $ 4.56 7.7 $ 3,321 Options vested and exercisable as of September 30, 2018 892,281 $ 3.47 6.5 $ 2,451 Restricted Stock Units Weighted- Weighted- Average Average Remaining Aggregate Grant Date Contractual Intrinsic Shares Fair Value Term (Years) Value (aggregate intrinsic value in thousands) Outstanding as of December 31, 2015 874,508 $ 5.95 1.8 $ 6,742 Granted 69,414 4.82 Released (438,086) 5.95 Forfeited/expired (14,882) 5.70 Outstanding as of December 31, 2016 490,954 5.80 0.5 $ 908 Granted 541,513 2.88 Released (497,009) 5.64 Forfeited/expired (25,564) 5.98 Outstanding as of December 31, 2017 509,894 2.84 1.4 $ 3,288 Granted 758,165 7.12 Released (178,380) 3.65 Forfeited/expired (15,486) 8.53 Outstanding as of September 30, 2018 1,074,193 $ 5.68 1.5 $ 6,391

Stock-based Compensation

Stock-based Compensation	9 Months Ended
	Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-based Compensation	Note 11. Stock-based Compensation. We record stock-based compensation based on fair value as of the grant date using the Black-Scholes option-pricing model for stock options granted and Monte Carlo simulation techniques for certain RSUs with performance-based vesting conditions. We recognize such costs as compensation expense on a straight-line basis over the employee’s requisite service period, which is generally four years. Our valuation assumptions for stock options are as follows: Fair value of common stock. Prior to our IPO in October 2015, we estimated the fair value of our common stock using various valuation methodologies, including valuation analyses performed by third-party valuation firms. After the IPO, we used the publicly quoted price as the fair value of our common stock. Risk-free interest rate. We base the risk-free interest rate used in the Black-Scholes option-pricing model on the implied yield available on U.S. Treasury zero-coupon issues with an equivalent expected term of the options for each option group. Expected term. The expected term represents the period that our stock-based awards are expected to be outstanding. The expected term assumption is based on the simplified method in which the expected term is equal to the average of the stock-based award’s weighted-average vesting period and its contractual term. We expect to continue using the simplified method until sufficient information about historical behavior is available. Volatility. We determine volatility based on the historical stock volatility of our publicly traded stock. Dividend yield. We have never declared or paid any cash dividend and do not currently plan to pay a cash dividend in the foreseeable future. Consequently, we used an expected dividend yield of zero. The following table summarizes the weighted-average assumptions used in the Black-Scholes option-pricing model to determine fair value of stock options: Three Months Ended Nine Months Ended September 30, September 30, 2018 2017 2018 2017 Volatility 77 % — 72 % 86 % Expected dividend yield — — — — Risk-free rate 2.80 % — 2.84 % 2.15 % Expected term (in years) 5 — 6 6 The weighted-average grant date fair value of the options granted under the 2015 Equity Incentive Plan as calculated using the Black-Scholes option-pricing model was $ 3.62 and $4.69 per share for the three and nine months ended September 30, 2018, respectively. On April 1, 2017, our compensation committee granted 204,220 RSUs that do not begin vesting unless certain performance goals are met. All performance goals must be met in order for the shares to begin vesting. Vesting would begin on the one-year anniversary of the grant date. These performance goals relate to a) the price performance of our common stock one year from the grant date as compared to a threshold established by our compensation committee and b) revenue, gross profit and EBITDA performance relative to plan targets for fiscal 2017 established by our compensation committee. As a result of these performance-based vesting conditions we valued these RSUs using Monte Carlo simulation techniques to establish a fair value per share of $0.81 at the time of grant. On April 1, 2018, our compensation committee granted 102,283 RSUs that do not begin vesting unless certain performance goals are met. Vesting will not begin unless the stock performance goals are met and the number of shares eligible to begin vesting are based on Adesto’s share performance as compared to the Russell 2000 stock index which is the performance threshold established by the compensation committee. The evaluation period for the stock performance is from April 2, 2018 through March 31, 2019. Vesting would begin on the one-year anniversary of the grant date with 20% of the shares vesting immediately and the remaining 80% of the shares vesting over the next eight quarters. As a result of these performance-based vesting conditions we valued these RSUs using Monte Carlo simulation techniques to establish a fair value per share of $4.92 at the time of grant. The following table presents the effects of stock-based compensation for stock options, RSUs (including performance-based RSUs), and ESPP purchase rights (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2018 2017 2018 2017 Cost of revenue $ 56 $ 35 $ 129 $ 86 Research and development 356 373 786 937 Sales and marketing 180 239 456 621 General and administrative 348 420 732 1,229 Total $ 940 $ 1,067 $ 2,103 $ 2,873 Stock-based compensation expense capitalized to inventories was not material during the three and nine months ended September 30, 2018 and 2017. We did not realize any income tax benefit from stock option exercises in any of the periods presented due to recurring losses and valuation allowances. As of September 30, 2018, the total unrecognized compensation cost related to stock options, net of estimated forfeitures, was approximately $ 3.0 million, and this amount is expected to be recognized over a weighted-average period of approximately 2.8 years. As of September 30, 2018, the total unrecognized compensation cost related to RSUs (including performance-based RSUs) and ESPP purchase rights was $ 4.8 million and $0.1 million, respectively, and these amounts are expected to be recognized over 2.5 years and 0.3 years, respectively.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Note 12. Income Taxes. We recorded a benefit from and provision for income tax of $64,000 and $17,000, respectively, for the three months ended September 30, 2018 and 2017, respectively, and a benefit from and provision for income tax of $80,000 and $57,000, respectively, for the nine months ended September 30, 2018 and 2017, respectively . The income tax provision is comprised of estimates of current and deferred taxes in domestic and foreign jurisdictions. The income tax provision reflects tax expense associated with foreign taxes, state income tax, uncertain tax positions and tax expense related to the recording of a deferred tax liability that results from the amortization for income tax purposes of acquisition-related goodwill. The decrease in the tax provision between 2018 and 2017 is primarily due to a deferred tax benefit associated with our foreign deferred tax liability. In December 2017, the Tax Cuts and Jobs Act (the “2017 Tax Act”) was enacted. The 2017 Tax Act includes a number of changes to existing U.S. tax laws that impact us, most notably a reduction of the U.S. corporate income tax rate from 35 percent to 21 percent for tax years beginning after December 31, 2017. On December 22, 2017, Staff Accounting Bulletin No. 118 ("SAB 118") was issued to address the application of U.S. GAAP in situations when a registrant does not have the necessary information available, prepared, or analyzed (including computations) in reasonable detail to complete the accounting for certain income tax effects of the 2017 Tax Act. In accordance with SAB 118, we have determined that the provisional amount related to the mandatory deemed repatriation of deferred foreign income was $0.1 million based on cumulative foreign earnings of $0.6 million. Additional work is necessary to do a more detailed analysis of historical foreign earnings as well as potential correlative adjustments. We are continuing to gather additional information to more precisely compute the amount of deferred foreign income to be included in U.S. taxable income. Any subsequent adjustment to these amounts will be recorded in the quarter of 2018 when the analysis is complete. In January 2018, the FASB released guidance on the accounting for tax on the global intangible low-taxed income ("GILTI") provisions of the 2017 Tax Act. The GILTI provisions impose a tax on foreign income in excess of a deemed return on tangible assets of foreign corporations. The guidance indicates that either accounting for deferred taxes related to GILTI inclusions or to treat any taxes on GILTI inclusions as period cost are both acceptable methods subject to an accounting policy election. Effective January 1, 2018, we elected to treat any potential GILTI inclusions as a period cost as we are not projecting any material impact from GILTI inclusions and any deferred taxes related to any inclusion would be immaterial. As of September 30, 2018, our deferred tax assets are fully offset by a valuation allowance except in those jurisdictions where it is determined that a valuation allowance is not required. Accounting for income taxes provides for the recognition of deferred tax assets if realization of such assets is more likely than not. Based on the weight of available evidence, which includes historical operating performance, reported cumulative net losses since inception and difficulty in accurately forecasting our future results, we provided a full valuation allowance against our net U.S. deferred tax assets. We reassess the need for our valuation allowance on a quarterly basis. If it is later determined that a portion or all of the valuation allowance is not required, it generally will be a benefit to the income tax provision in the period that such determination is made. We evaluate tax positions for recognition using a more-likely-than-not recognition threshold, and those tax positions eligible for recognition are measured as the largest amount of tax benefit that is greater than 50% likely of being realized upon the effective settlement with a taxing authority that has full knowledge of all relevant information. We believe that we have provided adequate reserves for our income tax uncertainties in all open tax years. We do not anticipate a material change in the total amount or composition of its unrecognized tax benefits within 12 months of September 30, 2018. We file federal, state and foreign income tax returns in jurisdictions with varying statutes of limitations. Due to our net operating loss and credit carryforwards, our income tax returns generally remain subject to examination by federal, state and international authorities.

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Net Loss Per Share	Note 13. Net Loss Per Share. The following outstanding common stock equivalents were excluded from the computation of diluted net loss per share for the periods presented because including them would have been antidilutive: Three Months Ended Nine Months Ended September 30, September 30, 2018 2017 2018 2017 Stock options 1,844,030 1,592,551 1,844,030 1,592,551 Restricted stock units 1,074,193 635,161 1,074,193 635,161 Common stock warrants 1,239,423 404,136 1,239,423 404,136 4,157,646 2,631,848 4,157,646 2,631,848

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2018
Related Party Transactions [Abstract]
Related Party Transactions	Note 14. Related Party Transactions. The Company purchases certain wafers from Altis Semiconductor S.N.C., which was acquired by X-FAB Silicon Foundries, a stockholder of the Company, in 2016. We made no payments to X-Fab Silicon Foundries during the three and nine months ended September 30, 2018. We made payments of $45,000 and $82,000 to X-FAB during the three and nine months ended September 30, 2017. As of September 30, 2018 and December 31, 2017, there were no invoices included within accounts payable on the condensed consolidated balance sheets.

Organization and Summary of S_2

Organization and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Nature of Operations	Organization and Nature of Operations. Adesto Technologies Corporation (together with its subsidiaries; “Adesto”, “we”, “our”, “us” or the “Company”) was incorporated in the state of California in January 2006 and reincorporated in Delaware in October 2015. We are a leading provider of innovative, application-specific semiconductor and systems for the Internet of Things era. Our corporate headquarters are located in Santa Clara, California. On May 9, 2018 we acquired 100% of the issued capital of S3 Asic Semiconductors Limited and on September 14, 2018 we acquired 100% of the issued capital of Echelon Corporation. Our financial results include the operating results of those entities from the date of acquisition.
Basis of Presentation	Basis of Presentation. The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) for interim financial information and with the instructions to Form 10‑Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP to complete annual consolidated financial statements. In the opinion of our management, all adjustments (consisting of normal recurring adjustments) considered necessary to present fairly the financial position of the Company and its results of operations and cash flows for the interim periods presented have been included. Operating results for the nine months ended September 30, 2018 are not necessarily indicative of the results that may be expected for the year ending December 31, 2018, for any other interim period or for any other future year. The condensed consolidated balance sheet as of December 31, 2017 was derived from the audited consolidated financial statements as of that date, but does not include all of the disclosures required by U.S. GAAP. The accompanying condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto contained in the Company’s Annual Report on Form 10‑K for the year ended December 31, 2017, filed with the Securities and Exchange Commission on March 13, 2018. The condensed consolidated financial statements include the results of our operations, and the operations of our wholly owned subsidiaries. All intercompany balances and transactions have been eliminated. There have been no material changes to our significant accounting policies described in Note 1, Organization and Summary of Significant Accounting Policies, in Notes to Consolidated Financial Statements in Item 8 of Part II of our Annual Report on Form 10‑K for the year ended December 31, 2017 that have had a material impact on our condensed consolidated financial statements and related notes, except as described below.
Recent Accounting Pronouncements and Recently Adopted Accounting Pronouncements	Recent Accounting Pronouncements. In August 2018, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2018-13, Fair Value Measurement Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement. As part of the FASB's disclosure framework project, it has eliminated, amended and added disclosure requirements for fair value measurements. Entities will no longer be required to disclose the amount of, and reasons for, transfers between Level 1 and Level 2 of the fair value hierarchy, the policy of timing of transfers between levels of the fair value hierarchy and the valuation processes for Level 3 fair value measurements. Public companies will be required to disclose the range and weighted average used to develop significant unobservable inputs for Level 3 fair value measurements. This ASU is effective for public entities for annual and interim periods beginning after December 15, 2019. Early adoption is permitted as of the beginning of any interim or annual reporting period. This ASU will have an impact on the Company's disclosures. In June 2018, FASB issued ASU No. 2018-07, Compensation—Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting. ASU 2018-07 applies to all entities that enter into share-based payment transactions for acquiring goods and services from nonemployees. The amendments in ASU 2018-07 expand the scope of Topic 718, Compensation - Stock Compensation, to include share-based payments transactions to nonemployees. Changes to the accounting for nonemployee awards as a result of ASU 2018-07 include: 1) equity-classified nonemployee share-based payment awards are measured at the grant date, instead of the previous requirement to remeasure the awards through the performance completion date, 2) for awards with performance conditions, compensation cost is recognized when the achievement of the performance condition is probable, rather than upon achievement, and 3) the current requirement to reassess the classification (equity or liability) for nonemployee awards upon vesting is eliminated. ASU 2018-07 clarifies that Topic 718 does not apply to financing transactions or awards granted to customers as part of a contract accounted for under Topic 606, Revenue from Contracts with Customers. The amendments in ASU 2018-07 are effective for public business entities for fiscal years beginning after December 15, 2018, and interim periods within that fiscal year. An entity should only remeasure liability-classified awards that have not been settled by the date of adoption and equity-classified awards for which the measurement date has not been established through a cumulative-effect adjustment to retained earnings as of the beginning of the fiscal year of adoption. The Company expects that the adoption will not have a material impact on its consolidated financial statements. In February 2018, FASB issued ASU No. 2018-02, Income Statement—Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. This ASU allows a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act. This ASU is effective for fiscal years beginning after December 15, 2018 and interim periods within those fiscal years. The Company expects that the adoption will not have a material impact on its consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-04, Intangibles—Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment. This ASU eliminates Step 2 from the goodwill impairment test. Instead, an entity should recognize an impairment charge for the amount by which the carrying value exceeds the reporting unit’s fair value, not to exceed the total amount of goodwill allocated to that reporting unit. This ASU is effective for annual or any interim goodwill impairment tests in fiscal years beginning after December 15, 2019. The Company is currently evaluating the effect of the adoption of this ASU, but anticipates that the adoption will not have a material impact on its consolidated financial statements. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. This ASU requires instruments measured at amortized cost to be presented at the net amount expected to be collected. Entities are also required to record allowances for available-for-sale debt securities rather than reduce the carrying amount. This ASU is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. The Company expects that the adoption will not have a material impact on its consolidated financial statements. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). The core principle of Topic 842 is that a lessee should recognize the assets and liabilities that arise from leases. For operating leases, a lessee is required to recognize a right-of-use asset and a lease liability, initially measured at the present value of the lease payments, in the statement of financial position. This ASU is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The Company is evaluating the effect that the adoption of this ASU will have on its consolidated financial statements. The Company currently expects that most of its operating lease commitments will be subject to the new standard and recognized as right-of-use assets and operating lease liabilities upon the adoption of ASU 2016-02, which will increase the total assets and total liabilities that it reports relative to such amounts prior to adoption. Recently Adopted Accounting Pronouncements. Adoption of ASC 606: In May 2014, the FASB issued an ASU on revenue from contracts with customers, ASU No. 2014-09, Revenue from Contracts with Customers (“Topic 606”). This standard update outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers. The guidance is effective for annual reporting periods including interim reporting reports beginning after December 15, 2017. Collectively, we refer to Topic 606, its related amendments and Subtopic 340-40 as the “new standard”. On January 1, 2018, we adopted the new standard using the modified retrospective method applied to all contracts that are not completed contracts at the date of initial application (i.e., January 1, 2018). Results for reporting periods after January 1, 2018 are presented under the new standard, while prior period amounts are not adjusted and continue to be reported in accordance with our historic accounting. There was no impact on the opening accumulated deficit as of January 1, 2018 due to the adoption of the new standard. We reclassified the allowance for ship from stock and debits (“SSDs”), price protection, rights of return and other activities to current liabilities presented as "Price adjustments and other revenue reserves" from the allowance for accounts receivable due to the adoption of the new standard. We recorded a cumulative effect adjustment to our January 1, 2018 condensed consolidated balance sheet for the impact of the reclassification of the allowance for SSDs, price protection, rights of return and other activities to current liabilities presented as “Price adjustments and other revenue reserves”. The cumulative effect of the changes made to our January 1, 2018 condensed consolidated balance sheet for the adoption of the new revenue standard were as follows (in thousands): Balance as of Adjustments Balance as of December 31, Due to January 1, 2017 ASC 606 2018 Accounts receivable, net $ 8,668 $ 3,832 $ 12,500 Price adjustments and other revenue reserves $ — $ (3,832) $ (3,832) In accordance with the new standard requirements, the disclosure of the impact of adoption on select condensed consolidated balance sheet line items was as follows (in thousands): As of September 30, 2018 As Balances without Effect of Reported ASC 606 Change Accounts receivable, net $ 24,706 $ 19,504 $ (5,202) Price adjustments and other revenue reserves $ 5,202 $ — $ 5,202
Revenue Recognition	As of September 30, 2018 As Balances without Effect of Reported ASC 606 Change Accounts receivable, net $ 24,706 $ 19,504 $ (5,202) Price adjustments and other revenue reserves $ 5,202 $ — $ 5,202 Revenue Recognition. Revenue is recognized when control of the promised goods or services is transferred to customers, in an amount that reflects the consideration we expect to be entitled to in exchange for those goods or services. Sales of products with alternative use account for the majority of our revenue and are recognized at a point in time, the timing of such recognition remained the same under Topic 606. Taxes assessed by a governmental authority that are both imposed on and concurrent with a specific revenue-producing transaction, that are collected by us from a customer and deposited with the relevant government authority, are excluded from revenue. Our revenue arrangements do not contain significant financing components. Revenue is recognized over a period of time when it is assessed that performance obligations are satisfied over a period rather than at a point in time. When any of the following criteria is fulfilled, revenue is recognized over a period of time: (a) The customer simultaneously receives and consumes the benefits provided by the performance as Adesto performs. (b) Adesto’s performance creates or enhances an asset (for example, work in process) that the customer controls as the asset is created or enhanced. (c) Adesto’s performance does not create an asset with an alternative use, and Adesto has an enforceable right to payment for performance completed to date. If revenue is recognized over a period of time, we would then select an appropriate method for measuring progress toward complete satisfaction of the performance obligation, usually costs incurred to date relative to the total expected costs to the satisfaction of that performance obligation. Typically, our revenue is recognized at a point in time. Sales to certain distributors are made under arrangements which provide the distributors with price adjustments, price protection, stock rotation and other allowances under certain circumstances. These adjustments and allowances are accounted for as variable consideration. We estimate these amounts based on the expected amount to be provided to customers and reduce revenue recognized. We believe that there will not be significant changes to our estimates of variable consideration. If a customer pays consideration, or Adesto has a right to an amount of consideration that is unconditional before we transfer a good or service to the customer, those amounts are classified as deferred income/ advances received from customers which are included in other current liabilities or other long-term liabilities when the payment is made or it is due, whichever is earlier. If the arrangement includes variable contingent consideration, we recognize revenue over time if we can reasonably measure its progress, or we are capable of providing reliable information that would be required to apply an appropriate method of measuring progress. To date, we have not had any arrangements incorporating contingent consideration. Practical Expedients and Elections. Sales commissions are owed and are recorded at the time of sell through of our products to end customers. These costs are recorded within sales and marketing expenses. We do not disclose the value of unsatisfied performance obligations for (i) contracts with an original expected length of one year or less and (ii) contracts for which we recognize revenue at the amount to which we have the right to invoice for services performed. We have elected to account for shipping and handling costs as fulfillment costs after the customer obtains control of the goods. These costs are recorded in cost of revenue.
Reclassifications	Reclassifications. Certain reclassifications have been made to prior periods’ condensed consolidated financial statements to conform to the current period presentation. These reclassifications did not result in any change in previously reported total assets, stockholders’ equity or net loss.
Use of Estimates	Use of Estimates. The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates, judgments and assumptions that affect the reported amount of assets, liabilities, revenue and expenses and related disclosures of contingent assets and liabilities. On an on-going basis, we evaluate those estimates, including those related to allowances for doubtful accounts, price adjustments and other revenue reserves, warranty accrual, inventory write-downs, valuation of long-lived assets, including property and equipment and identifiable intangible assets and goodwill, loss on purchase commitments, valuation of deferred taxes and contingencies. In addition, we use assumptions when employing the Black-Scholes option-pricing model to calculate the fair value of stock options granted and Monte Carlo simulation techniques to value certain restricted stock units with market-based vesting conditions. We base our estimates of the carrying value of certain assets and liabilities on historical experience and on various other assumptions that are believed to be reasonable under the circumstances, when these carrying values are not readily available from other sources. Actual results could differ from these estimates.
Product Warranty	Product Warranty. Our products are sold with a limited warranty for a period of one year, warranting that the product conforms to specifications and is free from material defects in design, materials and workmanship. To date, we have had insignificant returns of any defective production parts. During the year ended December 31, 2015, we recorded $250,000 for a specific potential warranty claim. During the years ended December 31, 2017 and 2016, $185,000 and $41,000, respectively, has been incurred relating to this potential warranty claim and during the year ended December 31, 2017 we recorded $27,000 for an additional potential warranty claim. As of September 30, 2018 and December 31, 2017, the warranty accrual was $51,000 and is included in accrued expenses and other current liabilities on the condensed consolidated balance sheets.
Foreign Currency Translation	Foreign Currency Translation. The functional currency of our foreign subsidiaries is the local currency. In consolidation, we translate assets and liabilities at exchange rates in effect at the consolidated balance sheet date. We translate revenue and expense accounts at the average exchange rates during the period in which the transaction takes place. Net losses from foreign currency translation of assets and liabilities were $ 148,000 and $20,000 for the three months ended September 30, 2018 and 2017, respectively, and $65,000 and $71,000 for the nine months ended September 30, 2018 and 2017, respectively, and are included in the cumulative translation adjustment component of accumulated other comprehensive loss, net of tax, a component of stockholders’ equity. Net gains and losses arising from transactions denominated in currencies other than the functional currency were a gain of $9,000 and a loss of $7,000 for the three months ended September 30, 2018 and 2017, respectively, and a loss of $1,000 and a gain of $1,000 for the nine months ended September 30, 2018 and 2017, respectively, and are included in other income (expense), net in the condensed consolidated statements of operations.
Concentration of Risk	Concentration of Risk. Our products are primarily manufactured, assembled and tested by third-party foundries and other contractors in Asia and we are heavily dependent on a single foundry in Taiwan for the manufacture of wafers and a single contractor in the Philippines for assembly and testing of our products. We do not have long-term agreements with either of these suppliers. A significant disruption in the operations of these parties would adversely impact the production of our products for a substantial period of time, which could have a material adverse effect on our business, financial condition, operating results and cash flows. Financial instruments that potentially subject us to significant concentrations of credit risk consist principally of cash and cash equivalents, investments and accounts receivables. We place substantially all of our cash and cash equivalents and investments on deposit with a reputable, high credit quality financial institution in the United States of America. We believe that the bank that holds substantially all of our cash and cash equivalents and investments is financially sound and, accordingly, subject to minimal credit risk. Deposits held with the bank may exceed the amount of insurance provided on such deposits. We generally do not require collateral or other security in support of accounts receivable. We periodically review the need for an allowance for doubtful accounts by considering factors such as historical experience, credit quality, the age of the accounts receivable balances and current economic conditions that may affect a customer’s ability to pay. The allowance for doubtful accounts as of September 30, 2018 and December 31, 2017 was $30,000 and zero, respectively. Customer concentrations as a percentage of revenue, net were as follows: Three Months Ended Nine Months Ended September 30, September 30, 2018 2017 2018 2017 Customer A 20 % 13 % 21 % 16 % Customer B * 12 % * 10 % Customer C * 13 % * 12 % * Customer concentrations as a percentage of gross accounts receivable were as follows: September 30, December 31, 2018 2017 Customer A 22 % 31 % Customer B 13 % *

Organization and Summary of S_3

Organization and Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Adoption of New Revenue Standard and Impact of Adoption on Select Condensed Consolidated Balance Sheet	The cumulative effect of the changes made to our January 1, 2018 condensed consolidated balance sheet for the adoption of the new revenue standard were as follows (in thousands): Balance as of Adjustments Balance as of December 31, Due to January 1, 2017 ASC 606 2018 Accounts receivable, net $ 8,668 $ 3,832 $ 12,500 Price adjustments and other revenue reserves $ — $ (3,832) $ (3,832) In accordance with the new standard requirements, the disclosure of the impact of adoption on select condensed consolidated balance sheet line items was as follows (in thousands): As of September 30, 2018 As Balances without Effect of Reported ASC 606 Change Accounts receivable, net $ 24,706 $ 19,504 $ (5,202) Price adjustments and other revenue reserves $ 5,202 $ — $ 5,202
Schedule of Customer Concentration as Percentage of Total Revenue and Gross Receivable	Customer concentrations as a percentage of revenue, net were as follows: Three Months Ended Nine Months Ended September 30, September 30, 2018 2017 2018 2017 Customer A 20 % 13 % 21 % 16 % Customer B * 12 % * 10 % Customer C * 13 % * 12 % * Customer concentrations as a percentage of gross accounts receivable were as follows: September 30, December 31, 2018 2017 Customer A 22 % 31 % Customer B 13 % *

Acquisition (Tables)

Acquisition (Tables)	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Business Acquisition [Line Items]
Schedule of Pro Forma Financial Information	Three Months Ended Nine Months Ended September 30, September 30, 2018 2017 2018 2017 (in thousands except per share amounts) Net revenue $ 27,541 $ 23,157 $ 76,780 $ 63,916 Net loss $ (8,124) $ (1,842) $ (17,087) $ (8,737) Basic and diluted net loss per share $ (0.29) $ (0.06) $ (0.72) $ (0.34)
Echelon Corporation [Member]
Business Acquisition [Line Items]
Schedule of Purchase Price Allocation	Cash $ 15,270 Short term investments 1,274 Accounts receivable 3,020 Inventories 5,710 Other current assets 2,845 Property and equipment, net 614 Intangible assets 17,690 Goodwill 4,266 Other non-current assets 252 Accounts payable (3,630) Other current liabilities (2,642) Other non-current liabilities (222) Deferred tax liability (341) Fair value net assets acquired $ 44,106
Schedule of Intangible Assets Acquired	Fair Value Useful Customer relationships $ 6,520 Developed technology 10,670 Trademarks 500 Total acquired intangible assets $ 17,690
S3 Asic Semiconductors Limited [Member]
Business Acquisition [Line Items]
Schedule of Purchase Price Allocation	Cash $ 267 Accounts receivable 192 Other current assets 883 Property and equipment, net 191 Intangible assets 15,340 Goodwill 34,352 Accounts payable (37) Deferred revenue (129) Earn-out liability, current (10,218) Other current liabilities (761) Deferred tax liability (1,918) Earn-out liability, non-current (3,279) Fair value of net assets acquired $ 34,883
Schedule of Intangible Assets Acquired		Fair Value Useful Customer relationships $ 12,880 7 Contract backlog 210 0.5 Developed technology 1,080 5 Non-compete agreements 380 2 Trademarks 790 12 Total $ 15,340

Balance Sheet Components (Table

Balance Sheet Components (Tables)	9 Months Ended
	Sep. 30, 2018
Balance Sheet Related Disclosures [Abstract]
Schedule of Accounts Receivable, Net	Accounts receivable, net consisted of the following (in thousands): September 30, December 31, 2018 2017 Accounts receivable $ 24,736 $ 12,500 Allowance for SSDs, price protection, rights of return and other activities — (3,832) Allowance for doubtful accounts (30) — Total accounts receivable, net $ 24,706 $ 8,668
Schedule of Inventories	Inventories consisted of the following (in thousands): September 30, December 31, 2018 2017 Raw materials $ 2,298 $ 2,213 Work-in-process 8,430 2,408 Finished goods 6,813 1,193 Total inventories $ 17,541 $ 5,814
Schedule of Property and Equipment, Net	Property and equipment, net consisted of the following (in thousands): September 30, December 31, 2018 2017 Machinery and equipment $ 14,936 $ 9,457 Leasehold improvements 4,463 4,252 Computer software 3,765 675 TowerJazz license 350 350 Furniture and fixtures 246 83 Construction in progress 1,301 1,301 Property and equipment, at cost 25,061 16,118 Accumulated depreciation and amortization (16,332) (8,935) Property and equipment, net $ 8,729 $ 7,183
Schedule of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consisted of the following (in thousands): September 30, December 31, 2018 2017 Accrued sales commission payable $ 318 $ 310 Accrued manufacturing expenses 537 265 Deferred rent, current portion 527 422 Liabilities to certain customers 812 468 Deferred revenue, current portion 1,454 262 Accrued professional services 1,903 94 Other accrued liabilities 1,418 538 Total accrued expenses and other current liabilities $ 6,969 $ 2,359

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Financial assets measured at fair value on a recurring basis	Fair Value Measurement at Reporting Date Using Significant Quoted Prices in Other Significant Active Markets Observable Unobservable for Identical Inputs Inputs Assets (Level 1) (Level 2) (Level 3) Total (in thousands) As of September 30, 2018 Assets: Money market funds $ 6 $ — $ — $ 6 U.S. government securities — 1,275 — 1,275 $ 6 $ 1,275 $ — $ 1,281 As of December 31, 2017 Assets: Money market funds $ 11,501 $ — $ — $ 11,501
Amortized cost basis, aggregate fair value, and gross unrealized holding gains and losses of short-term investments	Aggregate Unrealized Unrealized Amortized Cost Fair Value Holding Gain Holding Losses As of September 30, 2018 U.S. government securities $ 1,275 $ 1,275 $ — $ —

Intangible Assets, net (Tables)

Intangible Assets, net (Tables)	9 Months Ended
	Sep. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets	Intangible assets, net were as follows (in thousands): September 30, 2018 Estimated Useful Gross Carrying Accumulated Net Carrying Developed technology 10 $ 4,282 $ 2,570 $ 1,712 Developed technology 5 1,080 85 995 Developed technology 4 10,670 119 10,551 Customer relationships 12 9,011 4,505 4,506 Customer relationships 7 19,400 763 18,637 Customer backlog 1 2,779 2,779 — Contract backlog 0.5 210 165 45 Non-compete agreement 5 282 282 — Non-compete agreement 2 380 74 306 Trademarks 8 500 3 497 Trademarks 12 790 26 764 Total intangible assets subject to amortization $ 49,384 $ 11,371 $ 38,013 December 31, 2017 Estimated Useful Gross Carrying Accumulated Net Carrying Developed technology 10 $ 4,282 $ 2,249 $ 2,033 Customer relationships 12 9,011 3,942 5,069 Customer backlog 1 2,779 2,779 — Non-compete agreement 5 282 282 — Total intangible assets subject to amortization $ 16,354 $ 9,252 $ 7,102
Schedule of Amortization Expense of Intangible Assets	We recorded amortization expense related to the acquisition-related intangible assets as follows (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2018 2017 2018 2017 Operating expense category: Research and development $ 323 $ 121 $ 567 $ 364 Sales and marketing 763 188 1,472 563 General and administrative 52 — 80 — Total $ 1,138 $ 309 $ 2,119 $ 927
Schedule of Finite-Lived Intangible Assets, Annual Expected Amortization Expense	The estimated future amortization expense of acquisition-related intangible assets subject to amortization after September 30, 2018 is as follows (in thousands): Year Ended December 31, 2018 (remaining 3 months) $ 1,833 2019 7,152 2020 7,030 2021 6,962 2022 6,070 Thereafter 8,966 Total $ 38,013

Borrowings (Tables)

Borrowings (Tables)	9 Months Ended
	Sep. 30, 2018
Debt Disclosure [Abstract]
Schedule of Outstanding Borrowings	Outstanding borrowings consisted of the following (in thousands): September 30, December 31, 2018 2017 Term loan, current $ — $ 926 Term loan, non-current 29,433 10,908 Line of credit — 1,500 Total $ 29,433 $ 13,334
Schedule of Future Repayments Of Outstanding Borrowing	Future repayments on outstanding borrowings (excluding unamortized discount of $5.6 million as of September 30, 2018) are as follows (in thousands): Year Ended December 31, 2018 (remaining 3 months) $ 292 2019 1,750 2020 1,750 2021 1,750 2022 29,458 $ 35,000

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2018
Segment Reporting [Abstract]
Schedule of Product Revenue from Customers Based on Geographic Region	Product revenue from customers is disaggregated based on the geographic region to which the product is delivered. Revenue by geographic region was as follows (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2018 2017 2018 2017 United States $ 7,253 $ 3,331 $ 15,472 $ 8,853 Rest of Americas 583 58 868 189 Europe 5,087 2,044 11,708 6,054 Asia Pacific 8,865 9,729 27,078 24,540 Rest of world 139 77 286 322 Total $ 21,927 $ 15,239 $ 55,412 $ 39,958
Schedule of Long-Lived Assets by Geographic Region	Long-lived assets are attributed to the geographic region were they are located. Long-lived assets by geographic region were as follows (in thousands): September 30, December 31, 2018 2017 United States $ 5,511 $ 5,424 Asia Pacific 2,325 1,759 Europe 893 — Total property and equipment, net $ 8,729 $ 7,183

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Lease Payments Under Operating Leases	3 Total 2018 2019 2020 2021 2022 Thereafter (in thousands) Operating leases $ 7,994 $ 674 $ 2,148 $ 1,588 $ 1,466 $ 1,325 $ 793

Common Stock, Common Stock Wa_2

Common Stock, Common Stock Warrants and Stock Option Plan (Tables)	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Schedule of Stock Reserved for Future Issuance	September 30, December 31, 2018 2017 Warrants to purchase common stock 1,239,423 389,423 Stock option plan: Options outstanding 1,844,030 1,560,453 Restricted stock units outstanding 1,074,193 509,894 Shares available for future grants 289,258 580,827 Shares available for ESPP 362,938 275,587 Total 4,809,842 3,316,184
Summary of Outstanding Common Stock Warrants	As of September 30, 2018 Total amount of securities issuable under the outstanding warrants Exercise Price Issuance Date Expiration Date $ 30.35 2012-2013 $ 2.38 2014-2015 2022-2024 $ 8.30 $ 8.11 As of December 31, 2017 Total amount of securities issuable under the outstanding warrants Exercise Price Issuance Date Expiration Date $ 30.35 2012-2013 $ 2.38 2014-2015 2022-2024 $ 7.71
Summary of Stock Option Activity	Stock Options Weighted- Weighted- Average Average Remaining Aggregate Exercise Contractual Intrinsic Shares Price Term (Years) Value (aggregate intrinsic value in thousands) Outstanding as of December 31, 2015 796,356 2.49 6.5 $ 4,157 Granted 230,200 3.38 Exercised (13,112) 1.80 Canceled (21,549) 3.73 Outstanding as of December 31, 2016 991,895 2.68 6.3 $ 161 Granted 835,480 4.30 Exercised (230,123) 1.92 Canceled (36,799) 4.16 Outstanding as of December 31, 2017 1,560,453 3.63 7.6 $ 4,632 Granted 448,200 7.45 Exercised (108,222) 2.43 Canceled (56,401) 3.49 Outstanding as of September 30, 2018 1,844,030 $ 4.63 7.8 $ 3,397 Options vested and expected to vest as of September 30, 2018 1,750,842 $ 4.56 7.7 $ 3,321 Options vested and exercisable as of September 30, 2018 892,281 $ 3.47 6.5 $ 2,451
Summary of Restricted Stock Units Activity	Restricted Stock Units Weighted- Weighted- Average Average Remaining Aggregate Grant Date Contractual Intrinsic Shares Fair Value Term (Years) Value (aggregate intrinsic value in thousands) Outstanding as of December 31, 2015 874,508 $ 5.95 1.8 $ 6,742 Granted 69,414 4.82 Released (438,086) 5.95 Forfeited/expired (14,882) 5.70 Outstanding as of December 31, 2016 490,954 5.80 0.5 $ 908 Granted 541,513 2.88 Released (497,009) 5.64 Forfeited/expired (25,564) 5.98 Outstanding as of December 31, 2017 509,894 2.84 1.4 $ 3,288 Granted 758,165 7.12 Released (178,380) 3.65 Forfeited/expired (15,486) 8.53 Outstanding as of September 30, 2018 1,074,193 $ 5.68 1.5 $ 6,391

Stock-based Compensation (Table

Stock-based Compensation (Tables)	9 Months Ended
	Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Weighted Average Assumptions Used to Value Options	Three Months Ended Nine Months Ended September 30, September 30, 2018 2017 2018 2017 Volatility 77 % — 72 % 86 % Expected dividend yield — — — — Risk-free rate 2.80 % — 2.84 % 2.15 % Expected term (in years) 5 — 6 6
Schedule of Employee Service Share-based Compensation for Stock Options, Restricted Stock Units and ESPP Shares	The following table presents the effects of stock-based compensation for stock options, RSUs (including performance-based RSUs), and ESPP purchase rights (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2018 2017 2018 2017 Cost of revenue $ 56 $ 35 $ 129 $ 86 Research and development 356 373 786 937 Sales and marketing 180 239 456 621 General and administrative 348 420 732 1,229 Total $ 940 $ 1,067 $ 2,103 $ 2,873

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	Three Months Ended Nine Months Ended September 30, September 30, 2018 2017 2018 2017 Stock options 1,844,030 1,592,551 1,844,030 1,592,551 Restricted stock units 1,074,193 635,161 1,074,193 635,161 Common stock warrants 1,239,423 404,136 1,239,423 404,136 4,157,646 2,631,848 4,157,646 2,631,848

Organization and Summary of S_4

Organization and Summary of Significant Accounting Policies - Organization and Nature of Operations (Details)	Sep. 14, 2018	May 09, 2018
S3 Asic Semiconductors Limited [Member]
Business Acquisition, Date of Acquisition [Abstract]
Date of Acquisition		May 9, 2018
Business Combination, Description [Abstract]
Percentage of issued capital acquired (as a percent)		100.00%
Echelon Corporation [Member]
Business Acquisition, Date of Acquisition [Abstract]
Date of Acquisition	Sep. 14, 2018
Business Combination, Description [Abstract]
Percentage of issued capital acquired (as a percent)	100.00%

Organization and Summary of S_5

Organization and Summary of Significant Accounting Policies - Revenue Recognition - Adoption of ASC 606 (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Jan. 01, 2018	Dec. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net	$ 24,706	$ 12,500	$ 8,668	[1]
Price adjustments and other revenue reserves	5,202	(3,832)
Calculated under Revenue Guidance in Effect before Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net	19,504		$ 8,668
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net	5,202	3,832
Price adjustments and other revenue reserves	$ 5,202	$ (3,832)
[1]	The condensed consolidated balance sheet as of December 31, 2017 was derived from the audited consolidated financial statements as of that date.

Organization and Summary of S_6

Organization and Summary of Significant Accounting Policies - Revenue Recognition - Practical Expedients (Details)	9 Months Ended
	Sep. 30, 2018
Revenue, Remaining Performance Obligation, Optional Exemption [Abstract]
Revenue, Remaining Performance Obligation, Optional Exemption, Performance Obligation	true

Organization and Summary of S_7

Organization and Summary of Significant Accounting Policies - Product Warranty (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Product Warranties Disclosures [Abstract]
Product warranty	Our products are sold with a limited warranty for a period of one year, warranting that the product conforms to specifications and is free from material defects in design, materials and workmanship.
Product warranty period	1 year
Product warranty accrual recorded		$ 27		$ 250
Product warranty accrual	$ 51	51		$ 250
Product warranty accrual, current		51
Product warranty claim incurred		$ 185	$ 41

Organization and Summary of S_8

Organization and Summary of Significant Accounting Policies - Foreign Currency Translation (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Net gains and losses from foreign currency translation of assets and liabilities	$ (148)	$ (20)	$ (65)	$ (71)
Net gains and losses arising from transactions denominated in currencies other than the functional currency	$ 9	$ (7)	$ (1)	$ 1

Organization and Summary of S_9

Organization and Summary of Significant Accounting Policies - Concentrations Risk - Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Allowance for doubtful accounts	$ 30	$ 0

Organization and Summary of _10

Organization and Summary of Significant Accounting Policies - Concentrations Risk - Revenue (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Customer A [Member]
Concentration Risk [Line Items]
Concentration risk percentage (as a percent)	20.00%		21.00%
Sales Revenue, Net [Member] | Customer A [Member]
Concentration Risk [Line Items]
Concentration risk percentage (as a percent)				16.00%
Sales Revenue, Net [Member] | Customer B [Member]
Concentration Risk [Line Items]
Concentration risk percentage (as a percent)				10.00%
Sales Revenue, Net [Member] | Customer C [Member]
Concentration Risk [Line Items]
Concentration risk percentage (as a percent)				12.00%
Customer Concentration Risk [Member] | Customer A [Member]
Concentration Risk [Line Items]
Concentration risk percentage (as a percent)		13.00%
Customer Concentration Risk [Member] | Customer B [Member]
Concentration Risk [Line Items]
Concentration risk percentage (as a percent)		12.00%
Customer Concentration Risk [Member] | Customer C [Member]
Concentration Risk [Line Items]
Concentration risk percentage (as a percent)		13.00%

Organization and Summary of _11

Organization and Summary of Significant Accounting Policies - Concentrations Risk - Accounts Receivable (Details)	3 Months Ended		9 Months Ended	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Dec. 31, 2017
Customer A [Member]
Concentration Risk [Line Items]
Concentration risk percentage (as a percent)	20.00%		21.00%
Customer Concentration Risk [Member] | Customer A [Member]
Concentration Risk [Line Items]
Concentration risk percentage (as a percent)		13.00%
Customer Concentration Risk [Member] | Customer B [Member]
Concentration Risk [Line Items]
Concentration risk percentage (as a percent)		12.00%
Customer Concentration Risk [Member] | Accounts Receivable [Member] | Customer A [Member]
Concentration Risk [Line Items]
Concentration risk percentage (as a percent)			22.00%	31.00%
Customer Concentration Risk [Member] | Accounts Receivable [Member] | Customer B [Member]
Concentration Risk [Line Items]
Concentration risk percentage (as a percent)			13.00%

Acquisition - General Informati

Acquisition - General Information (Details)	Sep. 14, 2018	May 09, 2018
Echelon Corporation [Member]
Business Acquisition, Date of Acquisition [Abstract]
Date of Acquisition	Sep. 14, 2018
Business Combination, Description [Abstract]
Percentage of issued capital acquired (as a percent)	100.00%
S3 Asic Semiconductors Limited [Member]
Business Acquisition, Date of Acquisition [Abstract]
Date of Acquisition		May 9, 2018
Business Combination, Description [Abstract]
Percentage of issued capital acquired (as a percent)		100.00%

Acquisition - Consideration Tra

Acquisition - Consideration Transferred (Details) - USD ($) $ in Millions	Sep. 14, 2018	May 09, 2018
Echelon Corporation [Member]
Business Combination, Consideration Transferred [Abstract]
Cash consideration	$ 44.1
Aggregate consideration	$ 44.1
S3 Asic Semiconductors Limited [Member]
Business Combination, Consideration Transferred [Abstract]
Aggregate consideration		$ 35
Earn-out		$ 15

Acquisition - Fair Values of As

Acquisition - Fair Values of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Sep. 14, 2018	May 09, 2018	Dec. 31, 2017	[1]
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Goodwill	$ 38,640			$ 22
Echelon Corporation [Member]
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Cash		$ 15,270
Short term investments		1,274
Accounts receivable		3,020
Inventories		5,710
Other current assets		2,845
Property and equipment, net		614
Intangible assets		17,690
Goodwill		4,266
Other non-current assets		252
Accounts payable		(3,630)
Other current liabilities		(2,642)
Other non-current liabilities		(222)
Deferred tax liability		(341)
Fair value of net assets acquired		$ 44,106
S3 Asic Semiconductors Limited [Member]
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Cash			$ 267
Accounts receivable			192
Other current assets			883
Property and equipment, net			191
Intangible assets			15,340
Goodwill			34,352
Accounts payable			(37)
Deferred revenue			(129)
Earn-out liability, current			(10,218)
Other current liabilities			(761)
Deferred tax liability			(1,918)
Earn-out liability, non-current			(3,279)
Fair value of net assets acquired			$ 34,883
[1]	The condensed consolidated balance sheet as of December 31, 2017 was derived from the audited consolidated financial statements as of that date.

Acquisition - Intangible Assets

Acquisition - Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 14, 2018	May 09, 2018	Sep. 30, 2018
Echelon Corporation [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired	$ 17,690
Echelon Corporation [Member] | Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired	$ 6,520
Intangible assets, estimated useful life	7 years
Echelon Corporation [Member] | Developed Technology Rights [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired	$ 10,670
Intangible assets, estimated useful life	4 years		4 years
Echelon Corporation [Member] | Trademarks [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired	$ 500
Intangible assets, estimated useful life	8 years		8 years
S3 Asic Semiconductors Limited [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired		$ 15,340
S3 Asic Semiconductors Limited [Member] | Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired		$ 12,880
Intangible assets, estimated useful life		7 years	7 years
S3 Asic Semiconductors Limited [Member] | Order or Production Backlog [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired		$ 210
Intangible assets, estimated useful life		6 months	6 months
S3 Asic Semiconductors Limited [Member] | Developed Technology Rights [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired		$ 1,080
Intangible assets, estimated useful life		5 years	5 years
S3 Asic Semiconductors Limited [Member] | Noncompete Agreements [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired		$ 380
Intangible assets, estimated useful life		2 years	2 years
S3 Asic Semiconductors Limited [Member] | Trademarks [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired		$ 790
Intangible assets, estimated useful life		12 years	12 years

Acquisition - Pro Forma Financi

Acquisition - Pro Forma Financial Information (Details) - Echelon Corporation [Member] - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Business Acquisition, Pro Forma Information [Abstract]
Net revenue	$ 27,541	$ 23,157	$ 76,780	$ 63,916
Net loss	$ (8,124)	$ (1,842)	$ (17,087)	$ (8,737)
Basic net loss per share (in dollars per share)	$ (0.29)	$ (0.06)	$ (0.72)	$ (0.34)
Diluted net loss per share (in dollars per share)	$ (0.29)	$ (0.06)	$ (0.72)	$ (0.34)

Balance Sheet Components - Acco

Balance Sheet Components - Accounts Receivable, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Jan. 01, 2018	Dec. 31, 2017
Accounts Receivable, Net, Current [Abstract]
Accounts receivable	$ 24,736		$ 12,500
Allowance for SSDs, price protection, rights of return and other activities			(3,832)
Allowance for doubtful accounts	(30)		0
Total accounts receivable, net	$ 24,706	$ 12,500	$ 8,668	[1]
[1]	The condensed consolidated balance sheet as of December 31, 2017 was derived from the audited consolidated financial statements as of that date.

Balance Sheet Components - Inve

Balance Sheet Components - Inventories - Tabular Disclosure (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Inventory, Net [Abstract]
Raw materials	$ 2,298	$ 2,213
Work-in-process	8,430	2,408
Finished goods	6,813	1,193
Total inventories	$ 17,541	$ 5,814	[1]
[1]	The condensed consolidated balance sheet as of December 31, 2017 was derived from the audited consolidated financial statements as of that date.

Balance Sheet Components - In_2

Balance Sheet Components - Inventories - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Balance Sheet Related Disclosures [Abstract]
Inventory write-downs	$ 16
Realized benefit from sales of previously reserved products		$ 400	$ 900	$ 1,000

Balance Sheet Components - Prop

Balance Sheet Components - Property and Equipment - Tabular Disclosure (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Property Plant And Equipment [Line Items]
Property and equipment, at cost	$ 25,061	$ 16,118
Accumulated depreciation and amortization	(16,332)	(8,935)
Property and equipment, net	8,729	7,183	[1]
Machinery and Equipment [Member]
Property Plant And Equipment [Line Items]
Property and equipment, at cost	14,936	9,457
Leasehold Improvements [Member]
Property Plant And Equipment [Line Items]
Property and equipment, at cost	4,463	4,252
Software and Software Development Costs [Member]
Property Plant And Equipment [Line Items]
Property and equipment, at cost	3,765	675
Licensing Agreements [Member]
Property Plant And Equipment [Line Items]
Property and equipment, at cost	350	350
Furniture and Fixtures [Member]
Property Plant And Equipment [Line Items]
Property and equipment, at cost	246	83
Construction in Progress [Member]
Property Plant And Equipment [Line Items]
Property and equipment, at cost	$ 1,301	$ 1,301
[1]	The condensed consolidated balance sheet as of December 31, 2017 was derived from the audited consolidated financial statements as of that date.

Balance Sheet Components - Pr_2

Balance Sheet Components - Property and Equipment - Useful Lives (Details)	9 Months Ended
	Sep. 30, 2018
Tools, Dies and Molds [Member]
Property Plant And Equipment [Line Items]
Property and equipment, Estimated useful lives	3 years

Balance Sheet Components - Pr_3

Balance Sheet Components - Property and Equipment - Depreciation and Amortization (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Balance Sheet Related Disclosures [Abstract]
Depreciation and amortization	$ 0.6	$ 0.4	$ 1.7	$ 1

Balance Sheet Components - Accr

Balance Sheet Components - Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Balance Sheet Related Disclosures [Abstract]
Accrued sales commission payable	$ 318	$ 310
Accrued manufacturing expenses	537	265
Deferred rent, current portion	527	422
Liabilities to certain customers	812	468
Deferred revenue, current portion	1,454	262
Accrued professional services	1,903	94
Other accrued liabilities	1,418	538
Total accrued expenses and other current liabilities	$ 6,969	$ 2,359	[1]
[1]	The condensed consolidated balance sheet as of December 31, 2017 was derived from the audited consolidated financial statements as of that date.

Fair Value Measurements - Finan

Fair Value Measurements - Financial Assets Measured at Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Assets, Fair Value Disclosure [Abstract]
Debt securities, available-for-sale	$ 1,275
Debt securities, available-for-sale, type	us-gaap:USTreasuryAndGovernmentMember
Fair Value, Measurements, Recurring [Member]
Assets, Fair Value Disclosure [Abstract]
Debt securities, available-for-sale	$ 1,275
Assets, Fair Value Disclosure, Total	1,281
Fair Value, Measurements, Recurring [Member] | Money Market Funds [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents, fair value disclosure	6	$ 11,501
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Assets, Fair Value Disclosure, Total	6
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Money Market Funds [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents, fair value disclosure	6	$ 11,501
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Debt securities, available-for-sale	1,275
Assets, Fair Value Disclosure, Total	$ 1,275

Fair Value Measurements - Fin_2

Fair Value Measurements - Financial Liabilities Measured at Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial liabilities, fair value at recurring basis	$ 0	$ 0

Fair Value Measurements - Avail

Fair Value Measurements - Available-for-sale Securities - Contractual Maturities (Details)	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Debt securities, available-for-sale, type	us-gaap:USTreasuryAndGovernmentMember
Debt securities, available-for-sale, term	6 months
Debt securities, available-for-sale, average remaining term	3 months

Fair Value Measurements - Ava_2

Fair Value Measurements - Available-for-sale Securities - Fair Value to Amortized Cost (Details) $ in Thousands	Sep. 30, 2018USD ($)
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Debt securities, available-for-sale, type	us-gaap:USTreasuryAndGovernmentMember
Amortized cost	$ 1,275
Aggregate fair value	$ 1,275

Intangible Assets, net - Acquis

Intangible Assets, net - Acquisitions (Details) - USD ($) $ in Thousands	Sep. 14, 2018	May 09, 2018	Sep. 28, 2012
Certain Flash Memory Product Assets from Atmel Corporation [Member]
Finite Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired			$ 16,400
S3 Asic Semiconductors Limited [Member]
Finite Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired		$ 15,340
Echelon Corporation [Member]
Finite Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired	$ 17,690

Intangible Assets, net - Estima

Intangible Assets, net - Estimated Useful Life (Details)	Sep. 14, 2018	May 09, 2018	Sep. 30, 2018	Dec. 31, 2017
Developed Technology Rights [Member] | Certain Flash Memory Product Assets from Atmel Corporation [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets, estimated useful life			10 years	10 years
Developed Technology Rights [Member] | S3 Asic Semiconductors Limited [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets, estimated useful life		5 years	5 years
Developed Technology Rights [Member] | Echelon Corporation [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets, estimated useful life	4 years		4 years
Customer Relationships [Member] | Certain Flash Memory Product Assets from Atmel Corporation [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets, estimated useful life			12 years	12 years
Customer Relationships [Member] | S3 Asic Semiconductors Limited [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets, estimated useful life		7 years	7 years
Customer Relationships [Member] | Echelon Corporation [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets, estimated useful life	7 years
Order or Production Backlog [Member] | Certain Flash Memory Product Assets from Atmel Corporation [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets, estimated useful life			1 year	1 year
Order or Production Backlog [Member] | S3 Asic Semiconductors Limited [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets, estimated useful life		6 months	6 months
Noncompete Agreements [Member] | Certain Flash Memory Product Assets from Atmel Corporation [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets, estimated useful life			5 years	5 years
Noncompete Agreements [Member] | S3 Asic Semiconductors Limited [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets, estimated useful life		2 years	2 years
Trademarks [Member] | S3 Asic Semiconductors Limited [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets, estimated useful life		12 years	12 years
Trademarks [Member] | Echelon Corporation [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets, estimated useful life	8 years		8 years

Intangible Assets, net - Schedu

Intangible Assets, net - Schedule of Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	$ 49,384	$ 16,354
Accumulated amortization	11,371	9,252
Net carrying amount	38,013	7,102	[1]
Developed Technology Rights [Member] | Certain Flash Memory Product Assets from Atmel Corporation [Member]
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	4,282	4,282
Accumulated amortization	2,570	2,249
Net carrying amount	1,712	2,033
Developed Technology Rights [Member] | S3 Asic Semiconductors Limited [Member]
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	1,080
Accumulated amortization	85
Net carrying amount	995
Developed Technology Rights [Member] | Echelon Corporation [Member]
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	10,670
Accumulated amortization	119
Net carrying amount	10,551
Customer Relationships [Member] | Certain Flash Memory Product Assets from Atmel Corporation [Member]
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	9,011	9,011
Accumulated amortization	4,505	3,942
Net carrying amount	4,506	5,069
Customer Relationships [Member] | S3 Asic Semiconductors Limited [Member]
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	19,400
Accumulated amortization	763
Net carrying amount	18,637
Order or Production Backlog [Member] | Certain Flash Memory Product Assets from Atmel Corporation [Member]
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	2,779	2,779
Accumulated amortization	2,779	2,779
Order or Production Backlog [Member] | S3 Asic Semiconductors Limited [Member]
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	210
Accumulated amortization	165
Net carrying amount	45
Noncompete Agreements [Member] | Certain Flash Memory Product Assets from Atmel Corporation [Member]
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	282	282
Accumulated amortization	282	$ 282
Noncompete Agreements [Member] | S3 Asic Semiconductors Limited [Member]
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	380
Accumulated amortization	74
Net carrying amount	306
Trademarks [Member] | S3 Asic Semiconductors Limited [Member]
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	790
Accumulated amortization	26
Net carrying amount	764
Trademarks [Member] | Echelon Corporation [Member]
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	500
Accumulated amortization	3
Net carrying amount	$ 497
[1]	The condensed consolidated balance sheet as of December 31, 2017 was derived from the audited consolidated financial statements as of that date.

Intangible Assets, net - Amorti

Intangible Assets, net - Amortization Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Finite Lived Intangible Assets [Line Items]
Amortization expense, acquisition related intangible assets	$ 1,138	$ 309	$ 2,119	$ 927
Research and Development [Member]
Finite Lived Intangible Assets [Line Items]
Amortization expense, acquisition related intangible assets	323	121	567	364
Sales and Marketing [Member]
Finite Lived Intangible Assets [Line Items]
Amortization expense, acquisition related intangible assets	763	$ 188	1,472	$ 563
General and Administrative [Member]
Finite Lived Intangible Assets [Line Items]
Amortization expense, acquisition related intangible assets	$ 52		$ 80

Intangible Assets, net - Sche_2

Intangible Assets, net - Schedule of Finite-Lived Intangible Assets, Annual Expected Amortization Expense (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	[1]
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2018 (remaining 3 months)	$ 1,833
2,019	7,152
2,020	7,030
2,021	6,962
2,022	6,070
Thereafter	8,966
Net carrying amount	$ 38,013	$ 7,102
[1]	The condensed consolidated balance sheet as of December 31, 2017 was derived from the audited consolidated financial statements as of that date.

Investment in Unconsolidated _2

Investment in Unconsolidated Affiliates (Details) - USD ($) $ in Millions	Jun. 15, 2017	Jun. 30, 2018	Sep. 30, 2018	Dec. 31, 2017
Investment in Unconsolidated Affiliates
Notes receivable and accrued interest converted to shares	$ 0.4	$ 0.5
Shares resulting from the conversion of notes receivable and accrued interest (in shares)	233,335	312,076
Other Noncurrent Assets [Member] | Semitech Semiconductor Pty Ltd [Member]
Investment in Unconsolidated Affiliates
Investments in notes receivable			$ 0.1	$ 0.2

Borrowings - Western Alliance B

Borrowings - Western Alliance Bank Term Loan (Details) $ in Thousands	Sep. 29, 2017	Jul. 07, 2016USD ($)installment	May 31, 2018USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)
Debt Instrument [Line Items]
Amortization of debt discount				$ 707	$ 64
Term loan borrowings repaid				12,000	$ 4,909
Unamortized debt discount				$ 5,600
Western Alliance Bank Term Loan [Member]
Debt Instrument [Line Items]
Facility fee		$ 150
Debt instrument diligence fee		25
Debt Instrument additional fee liability		10
Unamortized debt discount		25
Secured Debt [Member] | Western Alliance Bank Term Loan [Member]
Debt Instrument [Line Items]
Debt instrument, face amount		$ 18,000
Borrowings mature date		Jun. 30, 2019
Debt instrument, description of payment terms		We made interest-only payments on the Term Loan from July 2016 through September 2016 and began making interest payments and principal payments in 33 equal monthly installments starting October 2016.
Number of monthly installments | installment		33
Term loan borrowings repaid			$ 12,000
Secured Debt [Member] | Western Alliance Bank Term Loan [Member] | Interest Expense [Member]
Debt Instrument [Line Items]
Unamortized debt discount			$ 66
Revolving Credit Facility [Member] | Western Alliance Bank Term Loan [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity		$ 5,000
Line of credit facility, maximum borrowing capacity as a percentage of eligible accounts receivable		80.00%
Borrowings mature date		Jul. 31, 2018
Prime Rate [Member] | Secured Debt [Member] | Western Alliance Bank Term Loan [Member]
Debt Instrument [Line Items]
Debt instrument, description of variable rate basis	The Term Loan bore interest at a rate per annum equal to the greater of the prime rate or 3.5%	The Term Loan bore interest at a rate per annum equal to the greater of the prime rate or 3.5%
Debt instrument, prime rate, minimum (as a percent)		3.50%
Debt instrument, basis spread on variable rate (as a percent)		0.75%
Prime Rate [Member] | Revolving Credit Facility [Member] | Western Alliance Bank Term Loan [Member]
Debt Instrument [Line Items]
Debt instrument, description of variable rate basis	The Line of Credit bore interest at a rate per annum equal to the greater of the prime rate or 3.5%	The Line of Credit bore interest at a rate per annum equal to the greater of the prime rate or 3.5%
Debt instrument, prime rate, minimum (as a percent)		3.50%
Debt instrument, basis spread on variable rate (as a percent)		0.50%

Borrowings - Cortland Capital M

Borrowings - Cortland Capital Market Services LLC Term Loan (Details) - USD ($) $ / shares in Units, $ in Thousands	May 08, 2018	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Debt Instrument [Line Items]
Unamortized debt discount		$ 5,600	$ 5,600
Amortization of debt discount			$ 707	$ 64
Common Stock Warrants [Member]
Debt Instrument [Line Items]
Number of shares warrants may purchase (in shares)		1,239,423	1,239,423		389,423
Exercise price (in dollars per share)		$ 8.11	$ 8.11		$ 7.71
Common Stock Warrants, Cortland Capital Market Services LLC Warrant [Member]
Debt Instrument [Line Items]
Number of warrants (in shares)	1
Number of shares warrants may purchase (in shares)	850,000	850,000	850,000
Number of shares each warrant may purchase (in shares)	850,000
Exercise price (in dollars per share)	$ 8.30	$ 8.30	$ 8.30
Term of warrant	6 years
Cortland Capital Market Services LLC Term Loan [Member] | Secured Debt [Member]
Debt Instrument [Line Items]
Debt instrument, face amount	$ 35,000
Borrowings mature date	May 8, 2022
Debt instrument, interest rate spread above otherwise applicable interest rate (as a percent)	2.00%
Financing costs paid	$ 1,400
Unamortized debt discount	$ 4,800
Amortization of debt discount		$ 400	$ 700
Cortland Capital Market Services LLC Term Loan [Member] | Secured Debt [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt instrument, description of variable rate basis	The Term Loan bears interest at a rate per annum equal to the sum of the Libor Rate (2.4375% on September 30, 2018)
Debt instrument, basis spread on variable rate (as a percent)	8.75%		2.4375%

Borrowings - Outstanding Borrow

Borrowings - Outstanding Borrowings (Details) - USD ($) $ in Thousands		Sep. 30, 2018	Dec. 31, 2017
Long-term Debt, Unclassified [Abstract]
Term loan, current	[1]		$ 926
Term loan, non-current		$ 29,433	10,908	[1]
Line of credit	[1]		1,500
Total		$ 29,433	$ 13,334
[1]	The condensed consolidated balance sheet as of December 31, 2017 was derived from the audited consolidated financial statements as of that date.

Borrowings - Unamortized Discou

Borrowings - Unamortized Discount (Details) $ in Millions	Sep. 30, 2018USD ($)
Debt Instrument, Unamortized Discount [Abstract]
Unamortized debt discount	$ 5.6

Borrowings - Future Repayments

Borrowings - Future Repayments on Outstanding Borrowings (Details) $ in Thousands	Sep. 30, 2018USD ($)
Long-term Debt, Fiscal Year Maturity [Abstract]
2018 (remaining 3 months)	$ 292
2,019	1,750
2,020	1,750
2,021	1,750
2,022	29,458
Borrowing outstanding prior to accounting for debt discount	$ 35,000

Borrowings - Interest Expense (

Borrowings - Interest Expense (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Interest Expense, Debt [Abstract]
Interest expense (excluding unamortized discount)	$ 1.1	$ 0.2	$ 2.4	$ 0.6

Segment Information - General I

Segment Information - General Information (Details) - segment	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Segment Reporting [Abstract]
Number of business segments	1	1	1	1

Segment Information - Revenue b

Segment Information - Revenue by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, net	$ 21,927	$ 15,239	$ 55,412	$ 39,958
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, net	7,253	3,331	15,472	8,853
Rest of Americas [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, net	583	58	868	189
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, net	5,087	2,044	11,708	6,054
Asia Pacific [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, net	8,865	9,729	27,078	24,540
Rest of World [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, net	$ 139	$ 77	$ 286	$ 322

Segment Information - Long-Live

Segment Information - Long-Lived Assets by Geographic Region (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	$ 8,729	$ 7,183	[1]
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	5,511	5,424
Asia Pacific [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	2,325	$ 1,759
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	$ 893
[1]	The condensed consolidated balance sheet as of December 31, 2017 was derived from the audited consolidated financial statements as of that date.

Commitments and Contingencies -

Commitments and Contingencies - Operating Leases (Details) - Headquarters Facility in Santa Clara [Member] $ in Thousands	Nov. 02, 2015USD ($)ft²	Sep. 30, 2018USD ($)	Dec. 31, 2017USD ($)
Operating Leased Assets [Line Items]
Base monthly rent during the extension period	$ 93
Area leased (in sqft) | ft²	34,000
Lease Expiration Date	Jul. 31, 2023
Optional Lease Extension Term	5 years
Annual increase of monthly rent after February 27, 2017	3.00%
Reimbursement for out-of-pocket costs associated with any tenant improvements	$ 2,500
Lease incentive obligation, noncurrent		$ 1,700	$ 2,000

Commitments and Contingencies_2

Commitments and Contingencies - Rent Expense (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Rent expense under operating leases	$ 0.5	$ 0.3	$ 1.2	$ 0.8

Commitments and Contingencies_3

Commitments and Contingencies - Future Minimum Lease Payments Under Operating Leases (Details) $ in Thousands	Sep. 30, 2018USD ($)
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Total	$ 7,994
2,018	674
2,019	2,148
2,020	1,588
2,021	1,466
2,022	1,325
Thereafter	$ 793

Commitments and Contingencies_4

Commitments and Contingencies - Purchase Commitments (Details) $ in Millions	9 Months Ended
	Sep. 30, 2018USD ($)
Purchase Commitments with Third-party Foundries [Member]
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Purchase commitments	$ 3.3
Licensing and Development Agreement [Member]
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Purchase commitments	$ 0.1
Purchase commitment, period	1 year
Agreement with TowerJazz Panasonic Semiconductor Company [Member]
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Purchase commitments	$ 0.4
Purchase commitment, period	1 year

Common Stock, Common Stock Wa_3

Common Stock, Common Stock Warrants and Stock Option Plan - Common Stock (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2018Vote$ / sharesshares	Dec. 31, 2017Vote$ / sharesshares
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Common stock, shares authorized (in shares) | shares	100,000,000	100,000,000
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Voting right common stock holder	Each holder of common stock is entitled to one vote per share.	Each holder of common stock is entitled to one vote per share.
Common stock, votes per share (in votes) | Vote	1	1
Common stock, dividends declared	$ 0	$ 0

Common Stock, Common Stock Wa_4

Common Stock, Common Stock Warrants and Stock Option Plan - Public Offering (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	9 Months Ended		12 Months Ended
	Jun. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2018
Subsidiary, Sale of Stock [Line Items]
Proceeds from public offering, net of underwriting discounts and commissions		$ 42,658	$ 18,363
Follow-on Offering [Member]
Subsidiary, Sale of Stock [Line Items]
Stock issued (in shares)	5,000,000			7,705,000
Share price (in dollars per share)	$ 4			$ 6
Proceeds from public offering, net of underwriting discounts and commissions	$ 18,400			$ 42,700
Over-Allotment Option [Member]
Subsidiary, Sale of Stock [Line Items]
Stock issued (in shares)	625,000			1,005,000

Common Stock, Common Stock Wa_5

Common Stock, Common Stock Warrants and Stock Option Plan - Stock Reserved for Future Issuance (Details) - shares	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2015
Class of Stock [Line Items]
Common stock, capital shares reserved for future issuance (in shares)	4,809,842	3,316,184
Common Stock Warrants [Member]
Class of Stock [Line Items]
Warrants to purchase common stock (in shares)	1,239,423	389,423
Stock Options [Member]
Class of Stock [Line Items]
Common stock, capital shares reserved for future issuance (in shares)	1,844,030	1,560,453
Restricted Stock Units (RSUs) [Member]
Class of Stock [Line Items]
Common stock, capital shares reserved for future issuance (in shares)	1,074,193	509,894
Shares available for future grants (in shares)	289,258	580,827
Employee Stock [Member]
Class of Stock [Line Items]
Common stock, capital shares reserved for future issuance (in shares)	362,938	275,587	150,000

Common Stock, Common Stock Wa_6

Common Stock, Common Stock Warrants and Stock Option Plan - Common Stock Warrants - Warrant Issued (Details) - USD ($) $ / shares in Units, $ in Millions	Sep. 30, 2018	May 08, 2018	Dec. 31, 2017
Class of Warrant or Right [Line Items]
Unamortized debt discount	$ 5.6
Cortland Capital Market Services LLC Term Loan [Member] | Secured Debt [Member]
Class of Warrant or Right [Line Items]
Unamortized debt discount		$ 4.8
Common Stock Warrants [Member]
Class of Warrant or Right [Line Items]
Number of shares warrants may purchase (in shares)	1,239,423		389,423
Exercise price (in dollars per share)	$ 8.11		$ 7.71
Common Stock Warrants, Cortland Capital Market Services LLC Warrant [Member]
Class of Warrant or Right [Line Items]
Number of warrants (in shares)		1
Number of shares warrants may purchase (in shares)	850,000	850,000
Number of shares each warrant may purchase (in shares)		850,000
Exercise price (in dollars per share)	$ 8.30	$ 8.30
Term of warrant		6 years

Common Stock, Common Stock Wa_7

Common Stock, Common Stock Warrants and Stock Option Plan - Common Stock Warrants - Fair Value Measurement Inputs (Details) - Common Stock Warrants, Cortland Capital Market Services LLC Warrant [Member]	May 08, 2018Y$ / shares
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, valuation technique	us-gaap:ValuationTechniqueOptionPricingModelMember
Measurement Input, Share Price [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input | $ / shares	8.70
Measurement Input, Expected Dividend Rate [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input	0
Measurement Input, Price Volatility [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input	0.6973
Measurement Input, Risk Free Interest Rate [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input	0.0287
Measurement Input, Expected Term [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input | Y	6

Common Stock, Common Stock Wa_8

Common Stock, Common Stock Warrants and Stock Option Plan - Common Stock Warrants - Tabular Disclosure (Details) - $ / shares	Sep. 30, 2018	May 08, 2018	Dec. 31, 2017
Common Stock Warrants [Member]
Class of Warrant or Right [Line Items]
Warrants to purchase common stock (in shares)	1,239,423		389,423
Exercise Price (in dollars per share)	$ 8.11		$ 7.71
Common Stock Warrants One [Member]
Class of Warrant or Right [Line Items]
Warrants to purchase common stock (in shares)	74,141		74,141
Exercise Price (in dollars per share)	$ 30.35		$ 30.35
Common Stock Warrants Two [Member]
Class of Warrant or Right [Line Items]
Warrants to purchase common stock (in shares)	315,282		315,282
Exercise Price (in dollars per share)	$ 2.38		$ 2.38
Common Stock Warrants, Cortland Capital Market Services LLC Warrant [Member]
Class of Warrant or Right [Line Items]
Warrants to purchase common stock (in shares)	850,000	850,000
Exercise Price (in dollars per share)	$ 8.30	$ 8.30

Common Stock, Common Stock Wa_9

Common Stock, Common Stock Warrants and Stock Option Plan - Common Stock Warrants - Additional Information (Details) - Common Stock Warrants [Member]	12 Months Ended
	Dec. 31, 2017shares
Class of Warrant or Right [Line Items]
Warrants expired (in shares)	7,378
Warrants exercised (in shares)	14,713
Shares issued upon exercising warrants (in shares)	10,223

Common Stock, Common Stock W_10

Common Stock, Common Stock Warrants and Stock Option Plan - 2007 Equity Incentive Plan (Details) - shares	9 Months Ended
	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2015	Oct. 26, 2015	Dec. 31, 2007	Jan. 31, 2007
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, capital shares reserved for future issuance (in shares)	4,809,842	3,316,184
Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, capital shares reserved for future issuance (in shares)	1,844,030	1,560,453
2007 Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, capital shares reserved for future issuance (in shares)			2,651,515		787,878	272,727
Percentage of fair market value of common stock (as a percent)	85.00%
Vesting period	4 years
Number of shares available for grant (in shares)				0
2007 Plan [Member] | New Employee [Member] | Share-based Compensation Award, Tranche One [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting percentage in year one (as a percent)	25.00%
2007 Plan [Member] | Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercisable period	10 years
2007 Plan [Member] | Restricted Stock [Member] | Persons controlling more than 10% of Company's stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of fair market value of common stock (as a percent)	100.00%

Common Stock, Common Stock W_11

Common Stock, Common Stock Warrants and Stock Option Plan - 2015 Equity Incentive Plan (Details) - shares	9 Months Ended
	Sep. 30, 2018	Dec. 31, 2017	Oct. 26, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, capital shares reserved for future issuance (in shares)	4,809,842	3,316,184
2015 Equity Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, capital shares reserved for future issuance (in shares)			1,813,272
Stock option grants description	The number of shares reserved for issuance under our 2015 Equity Incentive Plan will increase automatically on the first day of January of each of 2016 through 2025 by the number of shares equal to 4% of the total outstanding shares of our common stock as of the immediately preceding December 31.
Percentage threshold of outstanding shares increased annually under the plan (as a percent)	4.00%
Incentive stock options, maximum shares that may be issued (in shares)	25,000,000
Existing Employee [Member] | 2015 Equity Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock shares authorized for issuance (in shares)	2,000,000
New Employee [Member] | 2015 Equity Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock shares authorized for issuance (in shares)	4,000,000
Non Employee Director [Member] | 2015 Equity Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock shares authorized for issuance (in shares)	300,000

Common Stock, Common Stock W_12

Common Stock, Common Stock Warrants and Stock Option Plan - 2015 Employee Stock Purchase Plan (Details) - USD ($)	Jul. 31, 2018	Jan. 31, 2018	Jul. 29, 2016	Sep. 30, 2015	Sep. 30, 2018	Dec. 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, capital shares reserved for future issuance (in shares)					4,809,842	3,316,184
Employee Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, capital shares reserved for future issuance (in shares)				150,000	362,938	275,587
Employee stock purchase plan description					The number of shares reserved for issuance under our 2015 Employee Stock Purchase Plan will increase automatically on the first day of January following the first offering date by the number of shares equal to 1% of the total outstanding shares of our common stock as of the immediately preceding December 31 (rounded to the nearest whole share).
Percentage threshold of outstanding shares increased annually under the plan (as a percent)				1.00%
Common stock shares authorized for issuance (in shares)				2,250,000
Payroll deduction (as a percent)					15.00%
Percentage of fair market value of common stock (as a percent)					85.00%
Shares issued (in shares)	69,761	55,806	68,392			110,711
Maximum fair market value, that would permit employee to purchase common stock under plan					$ 25,000
Maximum number of shares issued each participants (in shares)					2,500

Common Stock, Common Stock W_13

Common Stock, Common Stock Warrants and Stock Option Plan - Stock Option Activity (Details) - Stock Options [Member] - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Shares
Outstanding, beginning of period (in shares)	1,560,453	991,895	796,356
Granted (in shares)	448,200	835,480	230,200
Exercised (in shares)	(108,222)	(230,123)	(13,112)
Cancelled (in shares)	(56,401)	(36,799)	(21,549)
Outstanding, end of period (in shares)	1,844,030	1,560,453	991,895	796,356
Weighted Average Exercise Price
Outstanding, beginning of period (in dollars per share)	$ 3.63	$ 2.68	$ 2.49
Granted (in dollars per share)	7.45	4.30	3.38
Exercised (in dollars per share)	2.43	1.92	1.80
Cancelled (in dollars per share)	3.49	4.16	3.73
Outstanding, end of period (in dollars per share)	$ 4.63	$ 3.63	$ 2.68	$ 2.49
Additional information
Weighted Average Remaining Contractual Term (Years)	7 years 9 months 18 days	7 years 7 months 6 days	6 years 3 months 18 days	6 years 6 months
Aggregate Intrinsic Value	$ 3,397	$ 4,632	$ 161	$ 4,157
Options vested and exercisable, end of period (in shares)	892,281
Options vested and exercisable, end of period (in dollars per share)	$ 3.47
Options vested and exercisable	6 years 6 months
Options vested and exercisable as of June 30, 2018	$ 2,451
Vested and expected to vest
Options vested and expected to vest, end of period (in shares)	1,750,842
Options vested and expected to vest, end of period (in dollars per share)	$ 4.56
Options vested and expected to vest	7 years 8 months 12 days
Options vested and expected to vest as of June 30, 2018	$ 3,321

Common Stock, Common Stock W_14

Common Stock, Common Stock Warrants and Stock Option Plan - Restricted Stock Units - Activity (Details) - Restricted Stock Units (RSUs) [Member] - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Shares
Outstanding, beginning of period (in shares)	509,894	490,954	874,508
Granted (in shares)	758,165	541,513	69,414
Released (in shares)	(178,380)	(497,009)	(438,086)
Forfeited/expired (in shares)	(15,486)	(25,564)	(14,882)
Outstanding, end of period (in shares)	1,074,193	509,894	490,954	874,508
Weighted Average Grant Date Fair Value
Outstanding, beginning of period (in dollars per share)	$ 2.84	$ 5.80	$ 5.95
Granted (in dollars per share)	7.12	2.88	4.82
Released (in dollars per share)	3.65	5.64	5.95
Forfeited/expired (in dollars per share)	8.53	5.98	5.70
Outstanding, end of period (in dollars per share)	$ 5.68	$ 2.84	$ 5.80	$ 5.95
Weighted Average Remaining Contractual Term (Years)
Weighted Average Remaining Contractual Term (Years)	1 year 6 months	1 year 4 months 24 days	6 months	1 year 9 months 18 days
Aggregate Intrinsic Value
Outstanding, end of period	$ 6,391	$ 3,288	$ 908	$ 6,742

Stock-based Compensation - Gene

Stock-based Compensation - General Information (Details) - Stock Options [Member]	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Employee's requisite service period		4 years
Expected dividend yield (as a percent)	0.00%	0.00%	0.00%

Stock-based Compensation - Weig

Stock-based Compensation - Weighted Average Assumptions Used to Value Options (Details) - Stock Options [Member]	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Volatility (as a percent)	77.00%	72.00%	86.00%
Expected dividend yield (as a percent)	0.00%	0.00%	0.00%
Risk-free rate (as a percent)	2.80%	2.84%	2.15%
Expected term (in years)	5 years	6 years	6 years

Stock-based Compensation - We_2

Stock-based Compensation - Weighted Average Grant Date Fair Value of Options Granted (Details) - $ / shares	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted-average grant date fair value of the options granted (in dollars per share)	$ 3.62	$ 4.69

Stock-based Compensation - Perf

Stock-based Compensation - Performance-based RSUs (Details) - Performance-based Restricted Stock Units [Member]	Apr. 01, 2018item$ / sharesshares	Apr. 01, 2017$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted (in shares) | shares	102,283	204,220
Vesting period	1 year	1 year
Number of quarters | item	8
Fair value per share at the time of grant (in dollars per share) | $ / shares	$ 4.92	$ 0.81
Vesting Immediately Member
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting percentage in year one (as a percent)	20.00%
Vesting Over Next Eight Quarters Member
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting percentage in year one (as a percent)	80.00%

Stock-based Compensation - Shar

Stock-based Compensation - Share-based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 940	$ 1,067	$ 2,103	$ 2,873
Cost of Revenue [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	56	35	129	86
Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	356	373	786	937
Sales and Marketing [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	180	239	456	621
General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 348	$ 420	$ 732	$ 1,229

Stock-based Compensation - Unre

Stock-based Compensation - Unrecognized Compensation Cost (Details) $ in Millions	9 Months Ended
	Sep. 30, 2018USD ($)
Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation cost	$ 3
Expected to be recognized over a weighted-average period	2 years 9 months 18 days
Restricted Stock Units (RSUs) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation cost	$ 4.8
Expected to be recognized over a weighted-average period	2 years 6 months
Employee Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation cost	$ 0.1
Expected to be recognized over a weighted-average period	3 months 18 days

Income Taxes - Provision (Detai

Income Taxes - Provision (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Provision for (benefit from) income taxes	$ (64)	$ 17	$ (80)	$ 57

Income Taxes - Tax Cuts and Job

Income Taxes - Tax Cuts and Jobs Act (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Federal tax at statutory rate (as a percent)	21.00%	35.00%
Provisional amount related to the mandatory deemed repatriation of deferred foreign income		$ 0.1
Cumulative foreign earnings		$ 0.6

Net Loss Per Share (Details)

Net Loss Per Share (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	4,157,646	2,631,848	4,157,646	2,631,848
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	1,844,030	1,592,551	1,844,030	1,592,551
Restricted Stock Units (RSUs) [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	1,074,193	635,161	1,074,193	635,161
Common Stock Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	1,239,423	404,136	1,239,423	404,136

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Related Party Transactions [Abstract]
Payments to related party	$ 0	$ 45	$ 0	$ 82
Accounts payable to related party	$ 0		$ 0		$ 0