ACM Research (ACMR) 10-Q8 Dec 172017 Q3 Quarterly reportFinancial data

Company Profile

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
Document and Entity Information - shares	Sep. 30, 2017	Dec. 05, 2017
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q3
Trading Symbol	ACMR
Entity Registrant Name	ACM RESEARCH, INC.
Entity Central Index Key	1,680,062
Current Fiscal Year End Date	--12-31
Entity Filer Category	Smaller Reporting Company
Class A Common Stock [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		12,935,546
Common Class B [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		2,409,738

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 17,074	$ 10,119
Restricted cash	433	0
Accounts receivable, less allowance for doubtful accounts of $0 and $0 at September 30, 2017 and December 31, 2016, respectively (note 3)	15,784	16,026
Loans receivable - related party (note 12)	946
Other receivables	2,017	1,763
Inventory (note 4)	18,077	11,666
Prepaid expenses	801	720
Other current assets	890	53
Total current assets	56,022	40,347
Property, plant and equipment, net (note 5)	2,346	2,262
Intangible assets, net	35	17
Deferred tax assets (note 17)	1,433	1,841
Investment in equity method affiliates (note 11)	1,220
Total assets	61,056	44,467
Current liabilities:
Short-term borrowings (note 6)	3,472	4,761
Notes payable	11	11
Investors' deposit (note 8)		2,902
Warrant liability (note 9)	3,033
Accounts payable (including amounts due to a related party of $1,925 and $508 at September 30, 2017 and December 31, 2016, respectively (note 12))	8,667	5,173
Advances from customers	75	215
Income tax payable	44	44
Other payables and accrued expenses (including amounts due to a related-party of $2,024 (unaudited) and $1,883 as of September 30, 2017 and December 31, 2016, respectively (note 12) (note 7))	5,264	3,963
Total current liabilities	20,566	17,069
Other long-term liabilities (note 10)	6,682	6,879
Total liabilities	27,248	23,948
Commitments and contingencies (Note 18)
Redeemable convertible preferred stock, par value $0.0001:
Redeemable convertible preferred stock	23,834	18,034
Stockholders' equity (deficit):
Additional paid in capital	19,244	7,620
Accumulated deficit	(13,344)	(9,643)
Accumulated other comprehensive loss	(109)	(413)
Total ACM Research, Inc. stockholders' equity (deficit)	5,793	(2,434)
Non-controlling interests	4,181	4,919
Total stockholders' equity	9,974	2,485
Total liabilities, redeemable convertible preferred stock and stockholders' equity	61,056	44,467
Series A Convertible Preferred Stock [Member]
Redeemable convertible preferred stock, par value $0.0001:
Redeemable convertible preferred stock	288	288
Series B Convertible Preferred Stock [Member]
Redeemable convertible preferred stock, par value $0.0001:
Redeemable convertible preferred stock	1,572	1,572
Series C Convertible Preferred Stock [Member]
Redeemable convertible preferred stock, par value $0.0001:
Redeemable convertible preferred stock	2,041	2,041
Series D Convertible Preferred Stock [Member]
Redeemable convertible preferred stock, par value $0.0001:
Redeemable convertible preferred stock	4,975	4,975
Series E Convertible Preferred Stock [Member]
Redeemable convertible preferred stock, par value $0.0001:
Redeemable convertible preferred stock	5,800
Series F Convertible Preferred Stock [Member]
Redeemable convertible preferred stock, par value $0.0001:
Redeemable convertible preferred stock	9,158	9,158
Class A Common Stock [Member]
Stockholders' equity (deficit):
Common stock	1	1
Common Class B [Member]
Stockholders' equity (deficit):
Common stock	1	$ 1
Pro Forma [Member]
Current assets:
Cash and cash equivalents	17,074
Restricted cash	433
Accounts receivable, less allowance for doubtful accounts of $0 and $0 at September 30, 2017 and December 31, 2016, respectively (note 3)	15,784
Loans receivable - related party (note 12)	946
Other receivables	2,017
Inventory (note 4)	18,077
Prepaid expenses	801
Other current assets	890
Total current assets	56,022
Property, plant and equipment, net (note 5)	2,346
Intangible assets, net	35
Deferred tax assets (note 17)	1,433
Investment in equity method affiliates (note 11)	1,220
Total assets	61,056
Current liabilities:
Short-term borrowings (note 6)	3,472
Notes payable	11
Warrant liability (note 9)	3,033
Accounts payable (including amounts due to a related party of $1,925 and $508 at September 30, 2017 and December 31, 2016, respectively (note 12))	8,667
Advances from customers	75
Income tax payable	44
Other payables and accrued expenses (including amounts due to a related-party of $2,024 (unaudited) and $1,883 as of September 30, 2017 and December 31, 2016, respectively (note 12) (note 7))	5,264
Total current liabilities	20,566
Other long-term liabilities (note 10)	6,682
Total liabilities	27,248
Commitments and contingencies (Note 18)
Stockholders' equity (deficit):
Additional paid in capital	43,078
Accumulated deficit	(13,344)
Accumulated other comprehensive loss	(109)
Total ACM Research, Inc. stockholders' equity (deficit)	29,627
Non-controlling interests	4,181
Total stockholders' equity	33,808
Total liabilities, redeemable convertible preferred stock and stockholders' equity	61,056
Pro Forma [Member] \| Class A Common Stock [Member]
Stockholders' equity (deficit):
Common stock	1
Pro Forma [Member] \| Common Class B [Member]
Stockholders' equity (deficit):
Common stock	$ 1

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Accounts receivable, allowance for doubtful accounts	$ 0	$ 0
Accounts payable, Due to a related party	1,925	508
Other payables and accrued expenses, due to a related-party	$ 2,024	$ 1,883
Redeemable convertible preferred stock, par value	$ 0.0001	$ 0.0001
Redeemable preferred stock, shares authorized	22,696,467
Series A Convertible Preferred Stock [Member]
Redeemable preferred stock, shares authorized	385,000	385,000
Redeemable preferred stock, shares issued	385,000	385,000
Redeemable preferred stock, shares outstanding	385,000	385,000
Redeemable preferred stock, liquidation value	$ 308	$ 308
Series B Convertible Preferred Stock [Member]
Redeemable preferred stock, shares authorized	1,572,000	1,572,000
Redeemable preferred stock, shares issued	1,572,000	1,572,000
Redeemable preferred stock, shares outstanding	1,572,000	1,572,000
Redeemable preferred stock, liquidation value	$ 1,572
Series C Convertible Preferred Stock [Member]
Redeemable preferred stock, shares authorized	1,360,962	1,360,962
Redeemable preferred stock, shares issued	1,360,962	1,360,962
Redeemable preferred stock, shares outstanding	1,360,962	1,360,962
Redeemable preferred stock, liquidation value	$ 2,041	$ 2,041
Series D Convertible Preferred Stock [Member]
Redeemable preferred stock, shares authorized	2,659,975	2,659,975
Redeemable preferred stock, shares issued	1,326,642	1,326,642
Redeemable preferred stock, shares outstanding	1,326,642	1,326,642
Redeemable preferred stock, liquidation value	$ 4,975	$ 4,975
Series E Convertible Preferred Stock [Member]
Redeemable preferred stock, shares authorized	10,718,530	10,718,530
Redeemable preferred stock, shares issued	4,998,508	0
Redeemable preferred stock, shares outstanding	4,998,508	0
Redeemable preferred stock, liquidation value	$ 4,999
Series F Convertible Preferred Stock [Member]
Redeemable preferred stock, shares authorized	6,000,000	6,000,000
Redeemable preferred stock, shares issued	3,663,254	3,663,254
Redeemable preferred stock, shares outstanding	3,663,254	3,663,254
Redeemable preferred stock, liquidation value	$ 9,158	$ 9,158
Class A Common Stock [Member]
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	4,741,635	2,228,740
Common stock, shares outstanding	4,741,635	2,228,740
Class A Common Stock [Member] \| Pro Forma [Member]
Common stock, par value	$ 0.0001
Common stock, shares authorized	100,000,000
Common stock, shares issued	9,369,212
Common stock, shares outstanding	9,369,212
Common Class B [Member]
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	7,303,533	7,303,533
Common stock, shares issued	2,409,738	2,409,738
Common stock, shares outstanding	2,409,738	2,409,738
Common Class B [Member] \| Pro Forma [Member]
Common stock, par value	$ 0.0001
Common stock, shares authorized	7,303,533
Common stock, shares issued	2,409,738
Common stock, shares outstanding	2,409,738

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Statement [Abstract]
Revenue	$ 4,891	$ 4,904	$ 19,314	$ 13,026
Cost of revenue	2,692	1,989	11,262	7,281
Gross profit	2,199	2,915	8,052	5,745
Operating expenses, net:
Sales and marketing	1,036	709	3,619	2,527
Research and development	1,209	813	3,076	2,299
General and administrative	1,264	605	4,422	1,694
Total operating expenses, net	3,509	2,127	11,117	6,520
Income (loss) from operations	(1,310)	788	(3,065)	(775)
Interest income	2	7	7	13
Interest expense	(33)	(67)	(197)	(118)
Equity in net income of affiliates	20		20
Non-operating income (expense), net	(239)	(35)	(531)	471
Income (loss) before income taxes	(1,560)	693	(3,766)	(409)
Income tax benefit (expense) (note 17)	278	(132)	(471)	(59)
Net income (loss)	(1,282)	561	(4,237)	(468)
Less: Net income (loss) attributable to non-controlling interests	(327)	199	(535)	(277)
Net income (loss) attributable to ACM Research, Inc.	(955)	362	(3,702)	(191)
Comprehensive income (loss):
Net income (loss)	(1,282)	561	(4,237)	(468)
Foreign currency translation adjustment	228	(66)	492	(199)
Comprehensive income (loss)	(1,054)	495	(3,745)	(667)
Less: Comprehensive income (loss) attributable to non-controlling interests	(237)	175	(347)	(351)
Total comprehensive income (loss) attributable to ACM Research, Inc.	$ (817)	$ 320	$ (3,398)	$ (316)
Net income (loss) per common shares (note 2)
Basic	$ (0.17)	$ 0.07	$ (0.72)	$ (0.09)
Diluted	$ (0.17)	$ 0.05	$ (0.72)	$ (0.09)
Weighted average common stocks outstanding used in computing per share amounts (note 2)
Basic	5,581,637	2,108,324	5,148,255	2,077,115
Diluted	5,581,637	3,372,505	5,148,255	2,077,115

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities:
Net loss	$ (4,237)	$ (468)
Adjustments to reconcile net loss from operations to net cash provided by (used in) operating activities:
Depreciation and amortization	183	134
Undistributed earnings from investments in equity method affiliates	(20)
Loss on disposals of fixed assets, intangible assets and other long-term assets		3
Deferred income taxes	491	58
Stock-based compensation	1,692	193
Net changes in operating assets and liabilities:
Restricted Cash	(433)
Accounts receivable	966	7,828
Other receivables	(170)	11
Inventory	(5,933)	(1,925)
Prepaid expenses	(20)	430
Other current assets	(836)	(20)
Accounts payable	3,242	1,000
Advances from customers	(180)	(4,487)
Other payables and accrued expenses	1,099	(307)
Other long-term liabilities	(505)	519
Net cash provided by (used in) operating activities	(4,661)	2,969
Cash flows from investing activities:
Purchase of property and equipment	(149)	(177)
Purchase of intangible assets	(37)	(22)
Proceed from disposal of property and equipment		8
Loan to related party	(946)
Purchase of non-controlling interest	(6,154)
Investments in unconsolidated equity method affiliates	(1,200)
Net cash used in investing activities	(8,486)	(191)
Cash flows from financing activities:
Proceeds from short-term borrowings	8,153	3,795
Repayments of short-term borrowings	(9,643)	(7,398)
Proceeds from stock option exercise to common stock	396	53
Proceed from issuance of Series E convertible preferred stock	5,800
Proceeds from issuance of Common Stock	15,300
Investor deposits for Series F convertible preferred stock		4,328
Net cash provided by financing activities	20,006	778
Effect of exchange rate changes on cash and cash equivalents	96	(114)
Net increase in cash and cash equivalents	6,955	3,442
Cash and cash equivalents at beginning of period	10,119	4,401
Cash and cash equivalents at end of period	17,074	7,843
Supplemental disclosure of cash flow information:
Interest paid	196	99
Income taxes paid	$ 0	$ 0

Description of Business

Description of Business	9 Months Ended
Description of Business	Sep. 30, 2017
Accounting Policies [Abstract]
Description of Business	NOTE 1 – DESCRIPTION OF BUSINESS ACM Research, Inc. (“ACM”) and its subsidiaries (collectively with ACM, the “Company”) develop, manufacture and sell single-wafer wet cleaning equipment used to improve the manufacturing process and yield for advanced integrated chips. The Company markets and sells, under the brand name “Ultra C,” lines of equipment based on the Company’s proprietary Space Alternated Phase Shift (“SAPS”) and Timely Energized Bubble Oscillation (“TEBO”) technologies. These tools are designed to remove random defects from a wafer surface efficiently, without damaging the wafer or its features, even at increasingly advanced process nodes. ACM was incorporated in California in 1998, and it initially focused on developing tools for manufacturing process steps involving the integration of ultra low-K In 2006 the Company established its operational center in Shanghai in the People’s Republic of China (the “PRC”), where it operates through ACM’s subsidiary ACM Research (Shanghai), Inc. (“ACM Shanghai”). ACM Shanghai was formed to help establish and build relationships with integrated circuit manufacturers in the PRC, and the Company financed its Shanghai operations in part through sales of non-controlling In 2007 the Company began to focus its development efforts on single-wafer wet-cleaning front-end two-dimensional wet-cleaning pre-existing back-end In 2011 ACM Shanghai formed a wholly owned subsidiary in the PRC, ACM Research (Wuxi), Inc. (“ACM Wuxi”), to manage sales and service operations. In November 2016 ACM redomesticated from California to Delaware pursuant to a merger in which ACM Research, Inc., a California corporation, was merged into a newly formed, wholly owned Delaware subsidiary, also named ACM Research, Inc. In June 2017 ACM formed a wholly owned subsidiary in Hong Kong, CleanChip Technologies Limited (“CleanChip”), to act on the Company’s behalf in Asian markets outside the PRC by, for example, serving as a trading partner between ACM Shanghai and its customers, procuring raw materials and components, performing sales and marketing activities, and making strategic investments. In August 2017 ACM purchased 18.77% of ACM Shanghai’s equity interests held by Shanghai Science and Technology Venture Capital Co., Ltd. (“SSTVC”). As of September 30, 2017, and December 31, 2016, respectively, ACM owned 81.64% and 62.87% of the outstanding equity interests of ACM Shanghai, and indirectly through ACM Shanghai, owned 81.64% and 62.87% of the outstanding equity interests of ACM Wuxi, respectively. In August 2017 ACM entered into securities purchase agreements pursuant to which ACM proposes to acquire the remaining outstanding non-controlling On September 13, 2017, ACM effectuated a 1-for-3

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
Summary of Significant Accounting Policies	Sep. 30, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	NOTE 2 – SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation and Principles of Consolidation The accompanying condensed consolidated financial statements of the Company have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). The consolidated accounts include ACM and its subsidiaries, ACM Shanghai, ACM Wuxi and CleanChip. Subsidiaries are those entities in which ACM, directly and indirectly, controls more than one half of the voting power. All significant intercompany transactions and balances have been eliminated upon consolidation. The accompanying condensed consolidated balance sheet as of September 30, 2017, the condensed consolidated statements of comprehensive income (loss) for the three and nine months ended September 30, 2017 and 2016, and the condensed consolidated statements of cash flows for the nine months ended September 30, 2017 and 2016 are unaudited. In the opinion of management, the unaudited condensed consolidated financial statements of the Company reflect all adjustments, which are necessary for a fair presentation of the Company’s financial position and results of operations. Such adjustments are of a normal recurring nature, unless otherwise noted. The balance sheet as of September 30, 2017 and the results of operations for the three and nine months ended September 30, 2017 are not necessarily indicative of the results to be expected for any future period. The condensed consolidated financial statements herein should be read in conjunction with the historical consolidated financial statements of the Company for the year ended December 31, 2016. Unaudited Pro Forma Balance Sheet The unaudited pro forma condensed consolidated balance sheet as of September 30, 2017 gives effect to the automatic conversion of all of the Company’s outstanding redeemable convertible preferred stock into shares of Class A common stock, which occurred upon completion of an IPO of common stock on November 7, 2017. Use of Estimates The preparation of condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the balance sheet date and the reported revenues and expenses during the reported period in the condensed consolidated financial statements and accompanying notes. The Company’s significant accounting estimates and assumptions include, but are not limited to, those used for the valuation and recognition of stock-based compensation arrangements and warrant liability, realization of deferred tax assets, assessment for impairment of long-lived assets, allowance for doubtful accounts, inventory valuation for excess and obsolete inventories, lower of cost and market value or net realizable value of inventories, depreciable lives of property and equipment, and useful life of intangible assets. Management of the Company believes that the estimates, judgments and assumptions are reasonable, based on information available at the time they are made. Actual results could differ materially from those estimates. Restricted Cash Restricted cash is money that is reserved for a specific purpose and therefore not available for immediate or general business use. At September 30, 2017 and December 31, 2016, restricted cash was $433 and $0, respectively. The restricted cash represents a deposit for a letter of credit issued for international purchase. Deferred Initial Public Offering (“IPO”) Costs Direct costs incurred by the Company attributable to its IPO of Class A common stock in the United States were deferred and recorded in other current assets and will be offset against the gross proceeds received from the IPO. At September 30, 2017 and December 31, 2016, deferred IPO costs were $819 and $41, respectively. Basic and Diluted Net Income (Loss) per Common Share Basic and diluted net income (loss) per common share is calculated as follows: Three Months Ended Nine Months Ended 2017 2016 2017 2016 Numerator: Net income (loss) $ (1,282 ) $ 561 $ (4,237 ) $ (468 ) Net income (loss) attributable to non-controlling (327 ) 199 (535 ) (277 ) Net income allocated to participating securities — 205 — — Net income (loss) available to common stockholders, basic and diluted $ (955 ) $ 157 $ (3,702 ) $ (191 ) Denominator: Weighted average shares outstanding, basic 5,581,637 2,108,324 5,148,255 2,077,115 Effect of dilutive securities — 1,264,181 — — Weighted average shares outstanding, diluted 5,581,637 3,372,505 5,148,255 2,077,115 Net income (loss) per common share: Basic $ (0.17 ) $ 0.07 $ (0.72 ) $ (0.09 ) Diluted $ (0.17 ) $ 0.05 $ (0.72 ) $ (0.09 ) Basic and diluted net income (loss) per common share is presented using the two-class two-class pro-rata, if-converted ACM has been authorized to issue Class A and Class B common stock since redomesticating in Delaware in November 2016. The two classes of common stock are substantially identical in all material respects, except for voting rights. Since ACM did not declare any dividends for the three and nine months ended September 30, 2017 and 2016, the net income (loss) per common share attributable to each class is the same under the “two-class” Diluted net income (loss) per common share reflects the potential dilution from securities that could share in ACM’s earnings. ACM’s potential dilutive securities consist of convertible preferred stocks, stock options and warrants for the three and nine months ended September 30, 2017 and 2016. Certain potential dilutive securities were excluded from the net income (loss) per share calculation because the impact would be anti-dilutive. Fair Value of Financial Instruments Under the authoritative guidance of the Financial Accounting Standards Board (“FASB”) on fair value measurements, fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. In determining the fair value, the Company uses various methods including market, income and cost approaches. Based on these approaches, the Company often utilizes certain assumptions that market participants would use in pricing the asset or liability, including assumptions about risk and the risks inherent in the inputs to the valuation technique. These inputs can be readily observable, market corroborated or generally unobservable inputs. The Company uses valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs. Based on observability of the inputs used in the valuation techniques, the Company is required to provide the following information according to the fair value hierarchy. The fair value hierarchy ranks the quality and reliability of the information used to determine fair values. Financial assets and liabilities carried at fair value are classified and disclosed in one of the following three categories: Level 1: Valuations for assets and liabilities traded in active exchange markets. Valuations are obtained from readily available pricing sources for market transactions involving identical assets or liabilities. Level 2: Valuations for assets and liabilities traded in less active dealer or broker markets. Valuations are obtained from third party pricing services for identical or similar assets or liabilities. Level 3: Valuations for assets and liabilities that are derived from other valuation methodologies, including option pricing models, discounted cash flow models and similar techniques, and not based on market exchange, dealer or broker traded transactions. Level 3 valuations incorporate certain unobservable assumptions and projections in determining the fair value assigned to such assets. All transfers between fair value hierarchy levels are recognized by the Company at the end of each reporting period. In certain cases, the inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, an investment’s level within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement in its entirety requires judgment, and considers factors specific to the investment. The inputs or methodology used for valuing financial instruments are not necessarily an indication of the risks associated with investment in those instruments. Fair Value Measured or Disclosed on a Recurring Basis Short-term borrowings Warrant liability Other financial items for disclosure purpose As of September 30, 2017 and December 31, 2016, information about inputs into the fair value measurement of the Company’s liabilities that are measured and recorded at fair value on a recurring basis in periods subsequent to their initial recognition is as follows: Fair Value Measurement at Reporting Date Using Quoted Prices in Significant Significant Total As of September 30: Liabilities: Short-term borrowings $ — $ 3,472 $ — $ 3,472 Warrant liability — — 3,033 3,033 — 3,472 3,033 6,505 As of December 31, 2016: Liabilities: Short-term borrowings $ — $ 4,761 $ — $ 4,761 Fair Value Measured on a Non-Recurring Basis The Company reviews long-lived assets for impairment annually or more frequently if events or changes in circumstances indicate the possibility of impairment. Long-lived assets are measured at fair value on a nonrecurring basis when there is an indicator of impairment, and they are recorded at fair value only when impairment is recognized. In determining the fair value, the Company used projections of cash flows directly associated with, and which are expected to arise as a direct result of, the use and eventual disposition of the assets. This approach required significant judgments including the Company’s projected net cash flows, which were derived using the most recent available estimate for the reporting unit containing the assets tested. Several key assumptions included periods of operation, projections of product pricing, production levels, product costs, market supply and demand, and inflation. Recent Accounting Pronouncements Accounting Pronouncements Recently Adopted in the Consolidated Financial Statements for the Nine Months Ended September 30, 2017 In April 2016, the FASB issued Accounting Standards Update (“ASU”) No. 2016-09, Compensation—Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting No. 2016-09 No. 2016-09 In November 2015, the FASB issued ASU No. 2015-17, Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes Income Taxes No. 2015-17 No. 2015-17 In July 2015, the FASB issued ASU No. 2015-11, Inventory (Topic 330): Simplifying the Measurement of Inventory No. 2015-11 No. 2015-11 last-in, first-out first-in, first-out last-in, first-out No. 2015-11 No. 2015-11 No. 2015-11 No. 2015-11 In August 2014, the FASB issued ASU No. 2014-15, Presentation of Financial Statements—Going Concern 205-40, Presentation of Financial Statements—Going Concern No. 2014-15 Recent Accounting Pronouncements Not Yet Adopted In July 2017, the FASB issued ASU No. 2017-11, Earnings Per Share (Topic 260); Distinguishing Liabilities from Equity (Topic 480); Derivatives and Hedging (Topic 815): (Part I) Accounting for Certain Financial Instruments with Down Round Features, (Part II) Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial Instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Noncontrolling Interests with a Scope Exception ASU No. 2017-11 In May 2017, the FASB issued ASU No. 2017-09, Compensation—Stock Compensation (Topic 718): Scope of Modification Accounting No. 2017-09 In February 2017, the FASB issued ASU No. 2017-05, Other Income—Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20): 610-20. 810-10. so-called 610-20 No. 2017-05 In January 2017, the FASB issued ASU No. 2017-04, Intangibles—Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment one-step 2017-04 In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash beginning-of-period end-of-period No. 2016-18 In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments zero-coupon No. 2016-15 In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) Leases Leases No. 2016-02 No. 2016-02 No. 2016-02 In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) No. 2014-09 Revenue Recognition (Topic 605) 2015-14, Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date No. 2015-14 No. 2014-09. not-for-profit No. 2014-09 No. 2014-09 No. 2015-14, 2016-08, Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net) 2016-10, Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing 2016-12, Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients 2016-20, Technical Corrections and Improvements to Topic 606, Revenue from Contracts with Customers No. 2016-08 No. 2016-10 No. 2016-10 No. 2016-12 non-cash No. 2016-20 No. 2016-08, No. 2016-10, No. 2016-12 No. 2016-20 No. 2014-09. No. 2014-09, No. 2016-08, No. 2016-10, No. 2016-12 No. 2016-20 Revenue from Contracts with Customers

Accounts Receivable

Accounts Receivable	9 Months Ended
Accounts Receivable	Sep. 30, 2017
Receivables [Abstract]
Accounts Receivable	NOTE 3 – ACCOUNTS RECEIVABLE At September 30, 2017 and December 31, 2016, accounts receivable consisted of the following: September 30, 2017 December 31, Accounts receivable $ 15,784 $ 16,026 Less: Allowance for doubtful accounts — — Total $ 15,784 $ 16,026 The Company reviews accounts receivable on a periodic basis and makes general and specific allowances when there is doubt as to the collectability of individual balances. No allowance for doubtful accounts was considered necessary at September 30, 2017 or December 31, 2016. At September 30, 2017 and December 31, 2016, no accounts receivable were pledged as collateral for borrowings from financial institutions.

Inventory

Inventory	9 Months Ended
Inventory	Sep. 30, 2017
Inventory Disclosure [Abstract]
Inventory	NOTE 4 – INVENTORY At September 30, 2017 and December 31, 2016, inventory consisted of the following: September 30, 2017 December 31, Raw materials $ 7,343 $ 7,698 Work in process 3,425 1,260 Finished goods 7,309 2,708 Total inventory, gross 18,077 11,666 Inventory reserve — — Total inventory, net $ 18,077 $ 11,666 At September 30, 2017 and December 31, 2016, the Company did not have an inventory reserve and no inventory was pledged as collateral for borrowings from financial institutions.

Property, Plant and Equipment,

Property, Plant and Equipment, Net	9 Months Ended
Property, Plant and Equipment, Net	Sep. 30, 2017
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment, Net	NOTE 5 – PROPERTY, PLANT AND EQUIPMENT, NET At September 30, 2017 and December 31, 2016, property, plant and equipment consisted of the following: September 30, 2017 December 31 Manufacturing equipment $ 9,515 $ 8,566 Office equipment 458 410 Transportation equipment 200 191 Leasehold improvement 243 224 Total cost 10,416 9,391 Less: Total accumulated depreciation (8,070 ) (7,562 ) Construction in progress — 433 Total property, plant and equipment, net $ 2,346 $ 2,262 Depreciation expense was $55 and $31 for the three months ended September 30, 2017 and 2016, respectively, and $162 and $119 for the nine months ended September 30, 2017 and 2016, respectively.

Short-Term Borrowings

Short-Term Borrowings	9 Months Ended
Short-Term Borrowings	Sep. 30, 2017
Debt Disclosure [Abstract]
Short-Term Borrowings	NOTE 6 – SHORT-TERM BORROWINGS At September 30, 2017 and December 31, 2016, short-term borrowing consisted of the following: September 30, December 31, Borrowings from Bank of China, due on February 10, 2017 with annual interest rate of 4.8%, secured by certain of the Company’s intellectual property and fully repaid on February 13, 2017 $ — $ 1,222 Borrowings from Bank of Shanghai Pudong Branch, due on June 24, 2017 with an annual interest rate of 5.66%, guaranteed by the Company’s CEO and fully repaid on June 25, 2017 — 281 Line of credit up to $3,605 from Bank of Shanghai Pudong Branch, due on July 3, 2017 with an annual interest rate of 5.66%, guaranteed by the Company’s CEO and fully repaid on June 7, 2017 — 1,455 Line of credit up to $3,670 from Bank of Shanghai Pudong Branch, due on July 3, 2017 with an annual interest rate of 3.2%, guaranteed by the Company’s CEO and fully repaid on May 18, 2017 — 1,803 Line of credit up to $4,521 from Bank of China Pudong Branch, due on March 5, 2018 with annual interest rate of 5.69%, secured by certain of the Company’s intellectual property 2,185 — Line of credit up to $3,767 from Bank of Shanghai Pudong Branch, due on September 22,2018 with an annual interest rate of 5.66%, guaranteed by the Company’s CEO 663 — Line of credit up to $3,767 from Bank of Shanghai Pudong Branch, due on September 23,2018 with an annual interest rate of 5.66%, guaranteed by the Company’s CEO 624 — Total $ 3,472 $ 4,761 Interest expense related to short-term borrowings amounted to $33 and $39 for the three months ended September 30, 2017 and 2016, respectively, and $196 and $150 for the nine months ended September 30, 2017 and 2016, respectively.

Other Payable and Accrued Expen

Other Payable and Accrued Expenses	9 Months Ended
Other Payable and Accrued Expenses	Sep. 30, 2017
Payables and Accruals [Abstract]
Other Payable and Accrued Expenses	NOTE 7 – OTHER PAYABLE AND ACCRUED EXPENSES At September 30, 2017 and December 31, 2016, other payable and accrued expenses consisted of the following: September 30, December 31, Lease expenses and payable for leasehold improvement due to a related party (note 12) $ 2,024 $ 1,883 Commissions 688 757 Accrued warranty 529 290 Accrued payroll 2 398 Accrued professional fees 908 46 Accrued machine testing fee 405 — Others 708 589 Total $ 5,264 $ 3,963

Investors' Deposits

Investors' Deposits	9 Months Ended
Investors' Deposits	Sep. 30, 2017
Banking and Thrift [Abstract]
Investors' Deposits	NOTE 8 – INVESTORS’ DEPOSITS On December 9, 2016, Shengxin (Shanghai) Management Consulting Limited Partnership (“SMC”), a related party (note 12), delivered RMB 20,124 (approximately $2,981 as of the close of business on such date) in cash (the “SMC Investment”) to ACM Shanghai for potential investment pursuant to terms to be subsequently negotiated. On March 14, 2017, ACM, ACM Shanghai and SMC entered into a securities purchase agreement pursuant to which, in exchange for the SMC Investment, ACM issued to SMC a warrant exercisable to purchase 397,502 shares of ACM’s Class A common stock at a price of $7.50 per share (note 9).

Warrant Liability

Warrant Liability	9 Months Ended
Warrant Liability	Sep. 30, 2017
Text Block [Abstract]
Warrant Liability	NOTE 9 – WARRANT LIABILITY On December 9, 2016, SMC delivered the SMC Investment to ACM Shanghai for potential investment pursuant to terms to be subsequently negotiated. As of December 31, 2016, the terms of the SMC Investment had not yet been negotiated and the SMC Investment was recorded as investors’ deposit. On March 14, 2017, ACM, ACM Shanghai and SMC entered into a securities purchase agreement (the “SMC Agreement”) pursuant to which, in exchange for the SMC Investment, ACM issued to SMC a warrant exercisable, for cash or on a cashless basis, to purchase, at any time on or before May 17, 2023, all, but not less than all, of 397,502 shares of ACM’s Class A common stock at a price of $7.50 per share. Under the SMC Agreement, if SMC does not exercise the warrant by May 17, 2023, ACM Shanghai will be obligated, subject to approval of governmental authorities and ACM Shanghai’s equity holders, to deliver an equity interest of 3.6394% (subject to dilution) in satisfaction of the SMC Investment. If SMC exercises the warrant or if SMC does not exercise the warrant and the issuance of the equity interest in ACM Shanghai is not completed by August 17, 2023 due to the inability of the parties to obtain required governmental or equity holder approvals, then ACM Shanghai will be obligated to pay to SMC, in satisfaction of the SMC Investment, an amount equal to $2,981, converted into RMB at the lesser of 6.75 and the then-current RMB-to-US In accordance with FASB ASC 480, Distinguishing Liabilities from Equity non-cash September 30, Fair value of common share (1) $ 7.23 Expected term in years (2) 5.63 Volatility (3) 28.73 % Risk-free interest rate (4) 1.92 % Expected dividend (5) 0 % (1) As the common stock was not publicly traded as of September 30. 2017, the Company used an independent third-party valuation firm to value the common stock price. (2) Expected term of the warrant represents the period from the current balance sheet date to the warrant expiration date. (3) Volatility is calculated based on the historical volatility of ACM’s comparable companies in the period equal to the expected term of the warrant. (4) Risk-free interest rate is based on the yields of U.S. Treasury securities with maturities similar to the expected term of the warrant. (5) Expected dividend is assumed to be 0% as ACM has no history or expectation of paying a dividend on its common stock.

Other Long-Term Liabilities

Other Long-Term Liabilities	9 Months Ended
Other Long-Term Liabilities	Sep. 30, 2017
Other Liabilities Disclosure [Abstract]
Other Long-Term Liabilities	NOTE 10 – OTHER LONG-TERM LIABILITIES Other long-term liabilities represent government subsidies received from PRC governmental authorities for development and commercialization of certain technology but not yet recognized. As of September 30, 2017, and December 31, 2016, other long-term liabilities consisted of the following unearned government subsidies: September 30, December 31, Subsidies to Stress Free Polishing project, commenced in 2008 $ 1,930 $ 1,958 Subsidies to Electro Copper Plating project, commenced in 2014 4,710 4,921 Subsidies to Patent project, commenced in 2017 42 — Total $ 6,682 $ 6,879

Equity Method Investment

Equity Method Investment	9 Months Ended
Equity Method Investment	Sep. 30, 2017
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investment	NOTE 11 – EQUITY METHOD INVESTMENT On September 6, 2017, ACM and Ninebell Co., Ltd. (“Ninebell”), a Korean company that is one of the Company’s principal materials suppliers, entered into an ordinary share purchase agreement, effective as of September 11, 2017, pursuant to which Ninebell issued to ACM ordinary shares representing 20% of Ninebell’s post-closing equity for a purchase price of $1,200, and a common stock purchase agreement, effective as of September 11, 2017, pursuant to which ACM issued 133,334 shares of Class A common stock to Ninebell for a purchase price of $1,000 at $7.50 per share. The investment in Ninebell is accounted for under the equity method. Undistributed earnings attributable to ACM’s equity method investment represented $20 of the consolidated retained earnings at September 30, 2017.

Related Party Balances and Tran

Related Party Balances and Transactions	9 Months Ended
Related Party Balances and Transactions	Sep. 30, 2017
Related Party Transactions [Abstract]
Related Party Balances and Transactions	NOTE 12 – RELATED PARTY BALANCES AND TRANSACTIONS On August 18, 2017, ACM and Ninebell, its equity method investment affiliate (note 11), entered into a loan agreement, pursuant to which ACM made an interest-free loan of $946 to Ninebell, payable in 180 days or automatically extended another 180 days if in default. The loan is secured by a pledge of Ninebell’s accounts receivable due from ACM and all money that Ninebell receives from ACM. ACM purchased materials from Ninebell amounting to $807 and $382 during the three months ended September 30, 2017 and 2016, respectively, and $2,624 and $1,446 during the nine months ended September 30, 2017 and 2016, respectively. As of September 30, 2017 and December 31, 2016, accounts payable due to Ninebell was $1,925 and $508, respectively. In 2007, ACM Shanghai entered into an operating lease agreement with Shanghai Zhangjiang Group Co., Ltd. (“Zhangjiang Group”), one of the holders of non-controlling On December 9, 2016, ACM Shanghai received the SMC Investment from SMC for potential investment pursuant to terms to be subsequently negotiated (notes 8 and 9). SMC is a limited partnership incorporated in the PRC, whose partners consist of employees of ACM Shanghai. As of September 30, 2017, and December 31, 2016, investors’ deposits from SMC amounted to $0, and $2,902, respectively. On March 14, 2017, ACM, ACM Shanghai and SMC entered into a securities purchase agreement (the “SMC Agreement”) pursuant to which, in exchange for the SMC Investment, ACM issued to SMC a warrant exercisable, for cash or on a cashless basis, to purchase, at any time on or before May 17, 2023, all, but not less than all, of 397,502 shares of ACM’s Class A common stock at a price of $7.50 per share, for a total exercise price of $2,981. Under the SMC Agreement, if SMC does not exercise the warrant by May 17, 2023, ACM Shanghai will be obligated, subject to approval of governmental authorities and ACM Shanghai’s equity holders, to deliver an equity interest of 3.6394% (subject to dilution) in satisfaction of the SMC Investment. If SMC exercises the warrant or if SMC does not exercise the warrant and the issuance of the equity interest in ACM Shanghai is not completed by August 17, 2023 due to the inability of the parties to obtain required governmental or equity holder approvals, then ACM Shanghai will be obligated to pay to SMC, in satisfaction of the SMC Investment, an amount equal to $2,981, converted into RMB at the lesser of 6.75 and the then-current RMB-to-US

Leases

Leases	9 Months Ended
Leases	Sep. 30, 2017
Leases [Abstract]
Leases	NOTE 13 – LEASES ACM entered into a two-year ACM Shanghai entered into an operating lease agreement with Zhangjiang Group (a related party, see note 12) in 2007 for manufacturing and office space of approximately 63,510 square feet in Shanghai, China. The lease agreement has been amended several times to modify payment terms and extend the lease term, most recently through December 31, 2017. Monthly rent is $58 during 2017. ACM Wuxi leases office space in Wuxi, China, at a rate of less than $1 per month. Future minimum lease payments under the non-cancelable September 30, December 31, 2017 $ 2,193 $ 2,538 2018 9 8 Total $ 2,202 $ 2,546 Rent expense was $140 and $168 for the three months ended September 30, 2017 and 2016, respectively, and $476 and $437 for the nine months ended September 30, 2017 and 2016, respectively.

Common Stock

Common Stock	9 Months Ended
Common Stock	Sep. 30, 2017
Equity [Abstract]
Common Stock	NOTE 14 – COMMON STOCK ACM is authorized to issue 100,000,000 shares of Class A common stock and 7,303,533 shares of Class B common stock, each with a par value of $0.0001. Each share of Class A common stock is entitled to one vote, and each share of Class B common stock is entitled to twenty votes and is convertible at any time into one share of Class A common stock. Shares of Class A common stock and Class B common stock are treated equally, identically and ratably with respect to any dividends if declared by the Board of Directors unless the Board of Directors declares different dividends to the Class A common stock and Class B common stock by getting approval from a majority of common stock holders. In August 2017 ACM entered into a securities purchase agreement with Shanghai Pudong High-Tech Investment Co., Ltd. (“PDHTI”) and its subsidiary Pudong Science and Technology (Cayman) Co., Ltd. (“PST”), in which ACM agreed to bid, in an auction process mandated by PRC regulations, to purchase PDHTI’s 10.78% equity interests in ACM Shanghai and to sell shares of Class A common stock to PST. On September 8, 2017, ACM issued 1,119,576 shares of Class A common stock to PST for a purchase price of $7.50 per share, representing an aggregate purchase price of $8,397. The non-controlling In August 2017 ACM entered into a securities purchase agreement with Shanghai Zhangjiang Science & Technology Venture Capital Co., Ltd. (“ZSTVC”) and its subsidiary Zhangjiang AJ Company Limited (“ZJAJ”), in which ACM agreed to bid, in an auction process mandated by PRC regulations, to purchase ZSTVC’s 7.58% equity interests in ACM Shanghai and to sell shares of Class A common stock to ZJAJ. On September 8, 2017, ACM issued 787,098 shares of Class A common stock to ZJAJ for a purchase price of $7.50 per share, or an aggregate purchase price of $5,903. The non-controlling In September 2017 ACM issued 133,334 shares of Class A common stock to Ninebell for a purchase price of $7.50 per share, or an aggregate purchase price of $1,000 (note 11). At various dates during the nine months ended September 30, 2017, ACM issued 472,887 shares of Class A common stock for options exercised by certain employee and non-employees. At September 30, 2017 and December 31, 2016, the number of shares of Class A common stock issued and outstanding was 4,741,635 and 2,228,740, respectively. At September 30, 2017 and December 31, 2016, the number of shares of Class B common stock issued and outstanding was 2,409,738.

Redeemable Convertible Preferre

Redeemable Convertible Preferred Stock	9 Months Ended
Redeemable Convertible Preferred Stock	Sep. 30, 2017
Text Block [Abstract]
Redeemable Convertible Preferred Stock	NOTE 15 – REDEEMABLE CONVERTIBLE PREFERRED STOCK Upon ACM’s redomestication in Delaware in November 2016, ACM had 22,696,467 authorized shares of preferred stock, of which 385,000, 1,572,000, 1,360,962, 2,659,975, 10,718,530, and 6,000,000 shares were designated as Series A, Series B, Series C, Series D, Series E and Series F preferred stock, respectively. In March 2017 ACM entered into a securities purchase agreement, amended in July 2017, with Shanghai Science and Technology Venture Capital Co., Ltd. (“SSTVC”) pursuant to which, effective as of August 31, 2017, ACM acquired SSTVC’s equity interests in ACM Shanghai for a purchase price of $6,154 (RMB 40,000) and issued to SSTVC 4,998,508 shares of Series E convertible preferred stock for a purchase price of $5,800. The number of outstanding shares of Series A, Series B, Series C, Series D, Series E and Series F was 385,000, 1,572,000, 1,360,962, 1,326,642, 4,998,508 and 3,663,254, and 385,000, 1,572,000, 1,360,962, 1,326,642, 0 and 3,663,254, respectively, at September 30, 2017 and December 31, 2016. Shares of ACM’s convertible preferred stock have rights, preferences and privileges as follows: Voting Rights Each share of Series A through Series F convertible preferred stock is entitled to a number of votes equal to the number of whole shares of common stock into which such share can be converted. Dividends Holders of Series A through Series F convertible preferred stock have a non-cumulative Conversion Each share of Series A through Series F convertible preferred stock is convertible at any time, at the option of the holder. At September 30, 2017, each share of Series A, B, E and F convertible preferred stock was convertible into one-third per-share Liquidation Preferences Holders of Series A through Series F convertible preferred stock are entitled to receive specified liquidation amounts in the event of a liquidation, dissolution or winding-up In the event of a liquidation, dissolution or winding-up

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
Stock-Based Compensation	Sep. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	NOTE 16 – STOCK-BASED COMPENSATION ACM’s stock-based compensation awards consisting of employee and non-employee Employee Awards The following table summarizes the Company’s employee share option activities during the nine months ended September 30, 2017: Number of Weighted Average Weighted Weighted Outstanding at January 1, 2017 2,100,377 $ 0.54 $ 2.03 7.83 Granted 83,334 2.58 7.50 Exercised (174,334 ) 0.45 0.75 Expired (903 ) 0.55 3.00 Forfeited (12,584 ) 0.54 3.00 Outstanding at September 30, 2017 1,995,890 $ 0.63 $ 2.37 7.77 Vested and exercisable at September 30, 2017 902,821 ACM recognized employee stock-based compensation expense of $72 and $22 during the three months ended September 30, 2017 and 2016, respectively, and $200 and $68 during the nine months ended September 30, 2017 and 2016, respectively. As of September 30, 2017, and December 31, 2016, $712 and $726, respectively, of total unrecognized employee stock-based compensation expense, net of estimated forfeitures, related to stock-based awards were expected to be recognized over a weighted-average period of 1.92 years and 2.25 years, respectively. Total recognized compensation cost may be adjusted for future changes in estimated forfeitures. The fair value of each option granted to an employee during the nine months ended September 30, 2017 was estimated on the grant date using the Black-Scholes valuation model with the following assumptions. No options were granted to employees during the nine months ended September 30, 2016. September 30, Fair value of common share (1) $ 7.59 Expected term in years (2) 6.25 Volatility (3) 29.18 % Risk-free interest rate (4) 2.22 % Expected dividend (5) 0 % (1) As the common stock was not publicly traded, the Company used an independent third-party valuation firm to value the common stock. (2) Expected term of share options is based on the average of the vesting period and the contractual term for each grant according to Staff Accounting Bulletin 110. (3) Volatility is calculated based on the historical volatility of ACM’s comparable companies in the period equal to the expected term of each grant. (4) Risk-free interest rate is based on the yields of U.S. Treasury securities with maturities similar to the expected term of the share options in effect at the time of grant. (5) Expected dividend is assumed to be 0% as ACM has no history or expectation of paying a dividend on its common stock. Non-employee The following table summarizes the Company’s non-employee Number of Weighted Weighted Weighted Average Outstanding at January 1, 2017 1,578,565 $ 0.51 $ 1.58 6.81 Granted 133,335 2.46 7.50 Exercised (298,555 ) 0.39 0.93 Expired (133,336 ) 0.45 0.75 Outstanding at September 30, 2017 1,280,009 $ 0.75 $ 2.43 7.70 Vested and exercisable at September 30, 2017 686,875 The Company recognized non-employee The fair value of each option granted to a non-employee non-employee September 30, 2017 Fair value of common share (1) $ 6.87-7.59 Expected term in years (2) 6.25 Volatility (3) 29.18%-29.51% Risk-free interest rate (4) 2.22%-2.43% Expected dividend (5) 0% (1) As the common stock was not publicly traded, the Company used an independent third-party valuation firm to value the common stock. (2) Expected term of share options is based on the average of the vesting period and the contractual term for each grant according to Staff Accounting Bulletin 110. (3) Volatility is calculated based on the historical volatility of ACM’s comparable companies in the period equal to the expected term of each grant. (4) Risk-free interest rate is based on the yields of U.S. Treasury securities with maturities similar to the expected term of the share options in effect at the time of grant. (5) Expected dividend is assumed to be 0% as ACM has no history or expectation of paying a dividend on its common stock.

Income Taxes

Income Taxes	9 Months Ended
Income Taxes	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Income Taxes	NOTE 17 – INCOME TAXES Income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carry-forwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period during which such rates are enacted. The Company considers all available evidence to determine whether it is more likely than not that some portion or all of the deferred tax assets will be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become realizable. Management considers the scheduled reversal of deferred tax liabilities (including the impact of available carryback and carry-forward periods), and projected taxable income in assessing the realizability of deferred tax assets. In making such judgments, significant weight is given to evidence that can be objectively verified. Based on all available evidence, in particular the Company’s three-year historical cumulative losses, recent operating losses and U.S. pre-tax In each period since inception, the Company has recorded a valuation allowance for the full amount of net deferred tax assets in the US, as the realization of deferred tax assets is uncertain. The China subsidiary has shown a three year historical cumulative profit and has projections of future income. As a result, the Company maintained a partial consolidated valuation allowance for the nine months ended September 30, 2017 and 2016. The Company accounts for uncertain tax positions in accordance with the authoritative guidance on income taxes under which the Company may only recognize or continue to recognize tax positions that meet a “more likely than not” threshold. The Company recognizes accrued interest and penalties related to unrecognized tax benefits as a component of the provision for income taxes. The Company’s effective tax rate differs from statutory rates of 34% for U.S. federal income tax purposes and 15%-25% book-tax As of September 30, 2017, the Company’s total unrecognized tax benefits were approximately $44, which would not affect the effective tax rate if recognized. The Company will recognize interest and penalties, when they occur, related to uncertain tax provisions as a component of tax expense. No interest or penalties were recognized for the nine months ended September 30, 2017. The Company files income tax returns in the United States, and state and foreign jurisdictions. The federal, state and foreign income tax returns are under the statute of limitations subject to tax examinations for the tax years ended December 31, 2009 through December 31, 2016. To the extent the Company has tax attribute carryforwards, the tax years in which the attribute was generated may be adjusted upon examination by the U.S. Internal Revenue Service, state or foreign tax authorities to the extent utilized in a future period. As of September 30, 2017 and December 31, 2016, the Company intended that its PRC earnings would be indefinitely reinvested outside of the United States. Thus, deferred taxes were not, for U.S. federal income tax purposes, provided with respect to unremitted earnings from the PRC.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
Commitments and Contingencies	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	NOTE 18 – COMMITMENTS AND CONTINGENCIES The Company leases offices under non-cancelable non-cancelable The Company did not have any capital commitments during the reported periods. From time to time the Company is subject to legal proceedings, including claims in the ordinary course of business and claims with respect to patent infringements.

Subsequent Events

Subsequent Events	9 Months Ended
Subsequent Events	Sep. 30, 2017
Subsequent Events [Abstract]
Subsequent Events	NOTE 19 – SUBSEQUENT EVENTS Under PRC regulations, PDHTI and ZSTVC could sell their minority ACM Shanghai equity interests (see note 14) only by means of auction processes. In October 2017 ACM was advised that its bids had won both auctions and that the sales of both of the minority equity interests would be completed by no later than December 31, 2017. Upon completion of the two auction processes, ACM will own all of the outstanding equity interests of ACM Shanghai. In November 2017 ACM issued and sold 2,233,000 shares of Class A common stock in the IPO. Of the shares sold in the IPO, 2,000,000 were sold upon completion of the IPO on November 7, 2017 and 233,000 shares were sold on November 14, 2017 upon exercise of an over-allotment option granted to the underwriters of the IPO. In addition, on November 7, 2017, following the completion of the IPO, ACM issued and sold 1,333,334 shares of Class A common stock in a private placement to two entities (the “Private Placement”). All of the 3,566,334 shares of Class A common stock issued in the IPO and the Private Placement were sold at a price of $5.60 per share, for aggregate gross proceeds of $20.0 million. The Company received approximately $16.5 million in net proceeds after deducting underwriting discounts and commissions, placement fees, and offering costs. • Upon the closing of the IPO on November 7, 2017, all of the outstanding shares of convertible preferred stock automatically converted into 4,627,577 shares of Class A common stock at the respective conversion rates then in effect. Following the closing of the IPO, there were no shares of preferred stock outstanding. • In connection with the IPO, ACM amended and restated its certificate of incorporation to change the authorized capital stock to 50,000,000 shares of Class A common stock, 2,409,738 shares of Class B common stock, and 10,000,000 shares designated as preferred stock, all with a par value of $0.0001 per share. The condensed consolidated financial statements as of September 30, 2017, including share and per share amounts, do not give effect to the IPO, the Private Placement, the conversion of the convertible preferred stock or the amendment and restatement of the certificate of incorporation as all of such events were completed subsequent to September 30, 2017.

Summary of Significant Accoun25

Summary of Significant Accounting Policies (Policies)	9 Months Ended
Summary of Significant Accounting Policies (Policies)	Sep. 30, 2017
Accounting Policies [Abstract]
Basis of Presentation and Principles of Consolidation	Basis of Presentation and Principles of Consolidation The accompanying condensed consolidated financial statements of the Company have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). The consolidated accounts include ACM and its subsidiaries, ACM Shanghai, ACM Wuxi and CleanChip. Subsidiaries are those entities in which ACM, directly and indirectly, controls more than one half of the voting power. All significant intercompany transactions and balances have been eliminated upon consolidation. The accompanying condensed consolidated balance sheet as of September 30, 2017, the condensed consolidated statements of comprehensive income (loss) for the three and nine months ended September 30, 2017 and 2016, and the condensed consolidated statements of cash flows for the nine months ended September 30, 2017 and 2016 are unaudited. In the opinion of management, the unaudited condensed consolidated financial statements of the Company reflect all adjustments, which are necessary for a fair presentation of the Company’s financial position and results of operations. Such adjustments are of a normal recurring nature, unless otherwise noted. The balance sheet as of September 30, 2017 and the results of operations for the three and nine months ended September 30, 2017 are not necessarily indicative of the results to be expected for any future period. The condensed consolidated financial statements herein should be read in conjunction with the historical consolidated financial statements of the Company for the year ended December 31, 2016.
Unaudited Pro Forma Balance Sheet	Unaudited Pro Forma Balance Sheet The unaudited pro forma condensed consolidated balance sheet as of September 30, 2017 gives effect to the automatic conversion of all of the Company’s outstanding redeemable convertible preferred stock into shares of Class A common stock, which occurred upon completion of an IPO of common stock on November 7, 2017.
Use of Estimates	Use of Estimates The preparation of condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the balance sheet date and the reported revenues and expenses during the reported period in the condensed consolidated financial statements and accompanying notes. The Company’s significant accounting estimates and assumptions include, but are not limited to, those used for the valuation and recognition of stock-based compensation arrangements and warrant liability, realization of deferred tax assets, assessment for impairment of long-lived assets, allowance for doubtful accounts, inventory valuation for excess and obsolete inventories, lower of cost and market value or net realizable value of inventories, depreciable lives of property and equipment, and useful life of intangible assets. Management of the Company believes that the estimates, judgments and assumptions are reasonable, based on information available at the time they are made. Actual results could differ materially from those estimate
Restricted Cash	Restricted Cash Restricted cash is money that is reserved for a specific purpose and therefore not available for immediate or general business use. At September 30, 2017 and December 31, 2016, restricted cash was $433 and $0, respectively. The restricted cash represents a deposit for a letter of credit issued for international purchase.
Deferred Initial Public Offering ("IPO") Costs	Deferred Initial Public Offering (“IPO”) Costs Direct costs incurred by the Company attributable to its IPO of Class A common stock in the United States were deferred and recorded in other current assets and will be offset against the gross proceeds received from the IPO. At September 30, 2017 and December 31, 2016, deferred IPO costs were $819 and $41, respectively.
Basic and Diluted Net Income (Loss) per Common Share	Basic and Diluted Net Income (Loss) per Common Share Basic and diluted net income (loss) per common share is calculated as follows: Three Months Ended Nine Months Ended 2017 2016 2017 2016 Numerator: Net income (loss) $ (1,282 ) $ 561 $ (4,237 ) $ (468 ) Net income (loss) attributable to non-controlling (327 ) 199 (535 ) (277 ) Net income allocated to participating securities — 205 — — Net income (loss) available to common stockholders, basic and diluted $ (955 ) $ 157 $ (3,702 ) $ (191 ) Denominator: Weighted average shares outstanding, basic 5,581,637 2,108,324 5,148,255 2,077,115 Effect of dilutive securities — 1,264,181 — — Weighted average shares outstanding, diluted 5,581,637 3,372,505 5,148,255 2,077,115 Net income (loss) per common share: Basic $ (0.17 ) $ 0.07 $ (0.72 ) $ (0.09 ) Diluted $ (0.17 ) $ 0.05 $ (0.72 ) $ (0.09 ) Basic and diluted net income (loss) per common share is presented using the two-class two-class pro-rata, if-converted ACM has been authorized to issue Class A and Class B common stock since redomesticating in Delaware in November 2016. The two classes of common stock are substantially identical in all material respects, except for voting rights. Since ACM did not declare any dividends for the three and nine months ended September 30, 2017 and 2016, the net income (loss) per common share attributable to each class is the same under the “two-class” Diluted net income (loss) per common share reflects the potential dilution from securities that could share in ACM’s earnings. ACM’s potential dilutive securities consist of convertible preferred stocks, stock options and warrants for the three and nine months ended September 30, 2017 and 2016. Certain potential dilutive securities were excluded from the net income (loss) per share calculation because the impact would be anti-dilutive.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Under the authoritative guidance of the Financial Accounting Standards Board (“FASB”) on fair value measurements, fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. In determining the fair value, the Company uses various methods including market, income and cost approaches. Based on these approaches, the Company often utilizes certain assumptions that market participants would use in pricing the asset or liability, including assumptions about risk and the risks inherent in the inputs to the valuation technique. These inputs can be readily observable, market corroborated or generally unobservable inputs. The Company uses valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs. Based on observability of the inputs used in the valuation techniques, the Company is required to provide the following information according to the fair value hierarchy. The fair value hierarchy ranks the quality and reliability of the information used to determine fair values. Financial assets and liabilities carried at fair value are classified and disclosed in one of the following three categories: Level 1: Valuations for assets and liabilities traded in active exchange markets. Valuations are obtained from readily available pricing sources for market transactions involving identical assets or liabilities. Level 2: Valuations for assets and liabilities traded in less active dealer or broker markets. Valuations are obtained from third party pricing services for identical or similar assets or liabilities. Level 3: Valuations for assets and liabilities that are derived from other valuation methodologies, including option pricing models, discounted cash flow models and similar techniques, and not based on market exchange, dealer or broker traded transactions. Level 3 valuations incorporate certain unobservable assumptions and projections in determining the fair value assigned to such assets. All transfers between fair value hierarchy levels are recognized by the Company at the end of each reporting period. In certain cases, the inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, an investment’s level within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement in its entirety requires judgment, and considers factors specific to the investment. The inputs or methodology used for valuing financial instruments are not necessarily an indication of the risks associated with investment in those instruments. Fair Value Measured or Disclosed on a Recurring Basis Short-term borrowings Warrant liability Other financial items for disclosure purpose As of September 30, 2017 and December 31, 2016, information about inputs into the fair value measurement of the Company’s liabilities that are measured and recorded at fair value on a recurring basis in periods subsequent to their initial recognition is as follows: Fair Value Measurement at Reporting Date Using Quoted Prices in Significant Significant Total As of September 30: Liabilities: Short-term borrowings $ — $ 3,472 $ — $ 3,472 Warrant liability — — 3,033 3,033 — 3,472 3,033 6,505 As of December 31, 2016: Liabilities: Short-term borrowings $ — $ 4,761 $ — $ 4,761 Fair Value Measured on a Non-Recurring Basis The Company reviews long-lived assets for impairment annually or more frequently if events or changes in circumstances indicate the possibility of impairment. Long-lived assets are measured at fair value on a nonrecurring basis when there is an indicator of impairment, and they are recorded at fair value only when impairment is recognized. In determining the fair value, the Company used projections of cash flows directly associated with, and which are expected to arise as a direct result of, the use and eventual disposition of the assets. This approach required significant judgments including the Company’s projected net cash flows, which were derived using the most recent available estimate for the reporting unit containing the assets tested. Several key assumptions included periods of operation, projections of product pricing, production levels, product costs, market supply and demand, and inflation
Recent Accounting Pronouncements	Recent Accounting Pronouncements Accounting Pronouncements Recently Adopted in the Consolidated Financial Statements for the Nine Months Ended September 30, 2017 In April 2016, the FASB issued Accounting Standards Update (“ASU”) No. 2016-09, Compensation—Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting No. 2016-09 No. 2016-09 In November 2015, the FASB issued ASU No. 2015-17, Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes Income Taxes No. 2015-17 No. 2015-17 In July 2015, the FASB issued ASU No. 2015-11, Inventory (Topic 330): Simplifying the Measurement of Inventory No. 2015-11 No. 2015-11 last-in, first-out first-in, first-out last-in, first-out No. 2015-11 No. 2015-11 No. 2015-11 No. 2015-11 In August 2014, the FASB issued ASU No. 2014-15, Presentation of Financial Statements—Going Concern 205-40, Presentation of Financial Statements—Going Concern No. 2014-15 Recent Accounting Pronouncements Not Yet Adopted In July 2017, the FASB issued ASU No. 2017-11, Earnings Per Share (Topic 260); Distinguishing Liabilities from Equity (Topic 480); Derivatives and Hedging (Topic 815): (Part I) Accounting for Certain Financial Instruments with Down Round Features, (Part II) Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial Instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Noncontrolling Interests with a Scope Exception ASU No. 2017-11 In May 2017, the FASB issued ASU No. 2017-09, Compensation—Stock Compensation (Topic 718): Scope of Modification Accounting No. 2017-09 In February 2017, the FASB issued ASU No. 2017-05, Other Income—Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20): 610-20. 810-10. so-called 610-20 No. 2017-05 In January 2017, the FASB issued ASU No. 2017-04, Intangibles—Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment one-step 2017-04 In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash beginning-of-period end-of-period No. 2016-18 In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments zero-coupon No. 2016-15 In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) Leases Leases No. 2016-02 No. 2016-02 No. 2016-02 In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) No. 2014-09 Revenue Recognition (Topic 605) 2015-14, Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date No. 2015-14 No. 2014-09. not-for-profit No. 2014-09 No. 2014-09 No. 2015-14, 2016-08, Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net) 2016-10, Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing 2016-12, Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients 2016-20, Technical Corrections and Improvements to Topic 606, Revenue from Contracts with Customers No. 2016-08 No. 2016-10 No. 2016-10 No. 2016-12 non-cash No. 2016-20 No. 2016-08, No. 2016-10, No. 2016-12 No. 2016-20 No. 2014-09. No. 2014-09, No. 2016-08, No. 2016-10, No. 2016-12 No. 2016-20 Revenue from Contracts with Customers

Summary of Significant Accoun26

Summary of Significant Accounting Policies (Tables)	9 Months Ended
Summary of Significant Accounting Policies (Tables)	Sep. 30, 2017
Accounting Policies [Abstract]
Calculation of Basic and Diluted Net Income (Loss) per Common Share	Basic and diluted net income (loss) per common share is calculated as follows: Three Months Ended Nine Months Ended 2017 2016 2017 2016 Numerator: Net income (loss) $ (1,282 ) $ 561 $ (4,237 ) $ (468 ) Net income (loss) attributable to non-controlling (327 ) 199 (535 ) (277 ) Net income allocated to participating securities — 205 — — Net income (loss) available to common stockholders, basic and diluted $ (955 ) $ 157 $ (3,702 ) $ (191 ) Denominator: Weighted average shares outstanding, basic 5,581,637 2,108,324 5,148,255 2,077,115 Effect of dilutive securities — 1,264,181 — — Weighted average shares outstanding, diluted 5,581,637 3,372,505 5,148,255 2,077,115 Net income (loss) per common share: Basic $ (0.17 ) $ 0.07 $ (0.72 ) $ (0.09 ) Diluted $ (0.17 ) $ 0.05 $ (0.72 ) $ (0.09 )
Information About Inputs Into Fair Value Measurement Of Company's Liabilities that Are Measured And Recorded At Fair Value On A Recurring Basis In Periods Subsequent To Their Initial Recognition	As of September 30, 2017 and December 31, 2016, information about inputs into the fair value measurement of the Company’s liabilities that are measured and recorded at fair value on a recurring basis in periods subsequent to their initial recognition is as follows: Fair Value Measurement at Reporting Date Using Quoted Prices in Significant Significant Total As of September 30: Liabilities: Short-term borrowings $ — $ 3,472 $ — $ 3,472 Warrant liability — — 3,033 3,033 — 3,472 3,033 6,505 As of December 31, 2016: Liabilities: Short-term borrowings $ — $ 4,761 $ — $ 4,761

Accounts Receivable (Tables)

Accounts Receivable (Tables)	9 Months Ended
Accounts Receivable (Tables)	Sep. 30, 2017
Receivables [Abstract]
Accounts Receivable	At September 30, 2017 and December 31, 2016, accounts receivable consisted of the following: September 30, 2017 December 31, Accounts receivable $ 15,784 $ 16,026 Less: Allowance for doubtful accounts — — Total $ 15,784 $ 16,026

Inventory (Tables)

Inventory (Tables)	9 Months Ended
Inventory (Tables)	Sep. 30, 2017
Inventory Disclosure [Abstract]
Inventory	At September 30, 2017 and December 31, 2016, inventory consisted of the following: September 30, 2017 December 31, Raw materials $ 7,343 $ 7,698 Work in process 3,425 1,260 Finished goods 7,309 2,708 Total inventory, gross 18,077 11,666 Inventory reserve — — Total inventory, net $ 18,077 $ 11,666

Property, Plant and Equipment29

Property, Plant and Equipment, Net (Tables)	9 Months Ended
Property, Plant and Equipment, Net (Tables)	Sep. 30, 2017
Property, Plant and Equipment [Abstract]
Property, plant and equipment	At September 30, 2017 and December 31, 2016, property, plant and equipment consisted of the following: September 30, 2017 December 31 Manufacturing equipment $ 9,515 $ 8,566 Office equipment 458 410 Transportation equipment 200 191 Leasehold improvement 243 224 Total cost 10,416 9,391 Less: Total accumulated depreciation (8,070 ) (7,562 ) Construction in progress — 433 Total property, plant and equipment, net $ 2,346 $ 2,262

Short-Term Borrowings (Tables)

Short-Term Borrowings (Tables)	9 Months Ended
Short-Term Borrowings (Tables)	Sep. 30, 2017
Debt Disclosure [Abstract]
Short-term borrowing	At September 30, 2017 and December 31, 2016, short-term borrowing consisted of the following: September 30, December 31, Borrowings from Bank of China, due on February 10, 2017 with annual interest rate of 4.8%, secured by certain of the Company’s intellectual property and fully repaid on February 13, 2017 $ — $ 1,222 Borrowings from Bank of Shanghai Pudong Branch, due on June 24, 2017 with an annual interest rate of 5.66%, guaranteed by the Company’s CEO and fully repaid on June 25, 2017 — 281 Line of credit up to $3,605 from Bank of Shanghai Pudong Branch, due on July 3, 2017 with an annual interest rate of 5.66%, guaranteed by the Company’s CEO and fully repaid on June 7, 2017 — 1,455 Line of credit up to $3,670 from Bank of Shanghai Pudong Branch, due on July 3, 2017 with an annual interest rate of 3.2%, guaranteed by the Company’s CEO and fully repaid on May 18, 2017 — 1,803 Line of credit up to $4,521 from Bank of China Pudong Branch, due on March 5, 2018 with annual interest rate of 5.69%, secured by certain of the Company’s intellectual property 2,185 — Line of credit up to $3,767 from Bank of Shanghai Pudong Branch, due on September 22,2018 with an annual interest rate of 5.66%, guaranteed by the Company’s CEO 663 — Line of credit up to $3,767 from Bank of Shanghai Pudong Branch, due on September 23,2018 with an annual interest rate of 5.66%, guaranteed by the Company’s CEO 624 — Total $ 3,472 $ 4,761

Other Payable and Accrued Exp31

Other Payable and Accrued Expenses (Tables)	9 Months Ended
Other Payable and Accrued Expenses (Tables)	Sep. 30, 2017
Payables and Accruals [Abstract]
Other payable and accrued expenses	At September 30, 2017 and December 31, 2016, other payable and accrued expenses consisted of the following: September 30, December 31, Lease expenses and payable for leasehold improvement due to a related party (note 12) $ 2,024 $ 1,883 Commissions 688 757 Accrued warranty 529 290 Accrued payroll 2 398 Accrued professional fees 908 46 Accrued machine testing fee 405 — Others 708 589 Total $ 5,264 $ 3,963

Warrant Liability (Tables)

Warrant Liability (Tables)	9 Months Ended
Warrant Liability (Tables)	Sep. 30, 2017
Text Block [Abstract]
Black-Scholes valuation model assumptions used to value warrant	The methodology used to value the warrant was the Black-Scholes valuation model with the following assumptions: September 30, Fair value of common share (1) $ 7.23 Expected term in years (2) 5.63 Volatility (3) 28.73 % Risk-free interest rate (4) 1.92 % Expected dividend (5) 0 % (1) As the common stock was not publicly traded as of September 30. 2017, the Company used an independent third-party valuation firm to value the common stock price. (2) Expected term of the warrant represents the period from the current balance sheet date to the warrant expiration date. (3) Volatility is calculated based on the historical volatility of ACM’s comparable companies in the period equal to the expected term of the warrant. (4) Risk-free interest rate is based on the yields of U.S. Treasury securities with maturities similar to the expected term of the warrant. (5) Expected dividend is assumed to be 0% as ACM has no history or expectation of paying a dividend on its common stock.

Other Long-Term Liabilities (Ta

Other Long-Term Liabilities (Tables)	9 Months Ended
Other Long-Term Liabilities (Tables)	Sep. 30, 2017
Other Liabilities Disclosure [Abstract]
Other long-term liabilities	As of September 30, 2017, and December 31, 2016, other long-term liabilities consisted of the following unearned government subsidies: September 30, December 31, Subsidies to Stress Free Polishing project, commenced in 2008 $ 1,930 $ 1,958 Subsidies to Electro Copper Plating project, commenced in 2014 4,710 4,921 Subsidies to Patent project, commenced in 2017 42 — Total $ 6,682 $ 6,879

Leases (Tables)

Leases (Tables)	9 Months Ended
Leases (Tables)	Sep. 30, 2017
Leases [Abstract]
Summary of Future Minimum Lease Payments under Non-cancelable Lease Agreements	Future minimum lease payments under the non-cancelable September 30, December 31, 2017 $ 2,193 $ 2,538 2018 9 8 Total $ 2,202 $ 2,546

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
Stock-Based Compensation (Tables)	Sep. 30, 2017
Employee Awards [Member]
Summary of Share Option Activities	The following table summarizes the Company’s employee share option activities during the nine months ended September 30, 2017: Number of Weighted Average Weighted Weighted Outstanding at January 1, 2017 2,100,377 $ 0.54 $ 2.03 7.83 Granted 83,334 2.58 7.50 Exercised (174,334 ) 0.45 0.75 Expired (903 ) 0.55 3.00 Forfeited (12,584 ) 0.54 3.00 Outstanding at September 30, 2017 1,995,890 $ 0.63 $ 2.37 7.77 Vested and exercisable at September 30, 2017 902,821
Summary of Assumptions used to Determine Fair Value of Share Options Granted	The fair value of each option granted to an employee during the nine months ended September 30, 2017 was estimated on the grant date using the Black-Scholes valuation model with the following assumptions. No options were granted to employees during the nine months ended September 30, 2016. September 30, Fair value of common share (1) $ 7.59 Expected term in years (2) 6.25 Volatility (3) 29.18 % Risk-free interest rate (4) 2.22 % Expected dividend (5) 0 % (1) As the common stock was not publicly traded, the Company used an independent third-party valuation firm to value the common stock. (2) Expected term of share options is based on the average of the vesting period and the contractual term for each grant according to Staff Accounting Bulletin 110. (3) Volatility is calculated based on the historical volatility of ACM’s comparable companies in the period equal to the expected term of each grant. (4) Risk-free interest rate is based on the yields of U.S. Treasury securities with maturities similar to the expected term of the share options in effect at the time of grant. (5) Expected dividend is assumed to be 0% as ACM has no history or expectation of paying a dividend on its common stock.
Non-employee Awards [Member]
Summary of Share Option Activities	The following table summarizes the Company’s non-employee Number of Weighted Weighted Weighted Average Outstanding at January 1, 2017 1,578,565 $ 0.51 $ 1.58 6.81 Granted 133,335 2.46 7.50 Exercised (298,555 ) 0.39 0.93 Expired (133,336 ) 0.45 0.75 Outstanding at September 30, 2017 1,280,009 $ 0.75 $ 2.43 7.70 Vested and exercisable at September 30, 2017 686,875
Summary of Assumptions used to Determine Fair Value of Share Options Granted	The fair value of each option granted to a non-employee non-employee September 30, 2017 Fair value of common share (1) $ 6.87-7.59 Expected term in years (2) 6.25 Volatility (3) 29.18%-29.51% Risk-free interest rate (4) 2.22%-2.43% Expected dividend (5) 0% (1) As the common stock was not publicly traded, the Company used an independent third-party valuation firm to value the common stock. (2) Expected term of share options is based on the average of the vesting period and the contractual term for each grant according to Staff Accounting Bulletin 110. (3) Volatility is calculated based on the historical volatility of ACM’s comparable companies in the period equal to the expected term of each grant. (4) Risk-free interest rate is based on the yields of U.S. Treasury securities with maturities similar to the expected term of the share options in effect at the time of grant. (5) Expected dividend is assumed to be 0% as ACM has no history or expectation of paying a dividend on its common stock.

Description of Business - Addit

Description of Business - Additional Information (Detail)	Sep. 13, 2017	Aug. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Class A Common Stock [Member]
Schedule Of Description Of Business [Line Items]
1-for-3 reverse stock split	3
Common Class B [Member]
Schedule Of Description Of Business [Line Items]
1-for-3 reverse stock split	3
ACM Shanghai [Member]
Schedule Of Description Of Business [Line Items]
Purchase of ACM Shanghai's equity interests		18.77%
Outstanding equity interest			81.64%	62.87%
ACM Wuxi [Member]
Schedule Of Description Of Business [Line Items]
Outstanding equity interest			81.64%	62.87%

Summary of Significant Accoun37

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Accounting Policies [Abstract]
Restricted cash	$ 433	$ 0
Deferred IPO costs	$ 819	$ 41

Summary of Significant Accoun38

Summary of Significant Accounting Policies - Calculation of Basic and Diluted Net Income (Loss) per Common Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Numerator:
Net income (loss)	$ (1,282)	$ 561	$ (4,237)	$ (468)
Net income (loss) attributable to non-controlling interest	(327)	199	(535)	(277)
Net income allocated to participating securities		205
Net income (loss) available to common stockholders, basic and diluted	$ (955)	$ 157	$ (3,702)	$ (191)
Denominator:
Weighted average shares outstanding, basic	5,581,637	2,108,324	5,148,255	2,077,115
Effect of dilutive securities		1,264,181
Weighted average shares outstanding, diluted	5,581,637	3,372,505	5,148,255	2,077,115
Net income (loss) per common share:
Basic	$ (0.17)	$ 0.07	$ (0.72)	$ (0.09)
Diluted	$ (0.17)	$ 0.05	$ (0.72)	$ (0.09)

Summary of Significant Accoun39

Summary of Significant Accounting Policies - Information About Inputs Into Fair Value Measurement Of Company's Liabilities that Are Measured And Recorded At Fair Value On A Recurring Basis In Periods Subsequent To Their Initial Recognition (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Liabilities:
Short-term borrowings	$ 3,472	$ 4,761
Warrant liability	3,033
Financial and Nonfinancial Liabilities, Fair Value Disclosure, Total	6,505
Significant Other Observable Inputs (Level 2) [Member]
Liabilities:
Short-term borrowings	3,472	$ 4,761
Financial and Nonfinancial Liabilities, Fair Value Disclosure, Total	3,472
Significant Unobservable Inputs (Level 3) [Member]
Liabilities:
Warrant liability	3,033
Financial and Nonfinancial Liabilities, Fair Value Disclosure, Total	$ 3,033

Accounts Receivable - Compositi

Accounts Receivable - Composition of Accounts Receivable (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Receivables [Abstract]
Accounts receivable	$ 15,784	$ 16,026
Less: Allowance for doubtful accounts	0	0
Total	$ 15,784	$ 16,026

Accounts Receivable - Additiona

Accounts Receivable - Additional Information (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Receivables [Abstract]
Allowance for doubtful accounts	$ 0	$ 0
Accounts receivable were pledged as collateral for borrowings	$ 0	$ 0

Inventory - Details of Inventor

Inventory - Details of Inventory (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Inventory Disclosure [Abstract]
Raw materials	$ 7,343	$ 7,698
Work in process	3,425	1,260
Finished goods	7,309	2,708
Total inventory, gross	18,077	11,666
Inventory reserve	0	0
Total inventory, net	$ 18,077	$ 11,666

Inventory - Additional Informat

Inventory - Additional Information (Detail) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Inventory Disclosure [Abstract]
Inventory reserve	$ 0	$ 0
Inventory pledged as collateral for borrowings	$ 0	$ 0

Property, Plant and Equipment (

Property, Plant and Equipment (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Total cost	$ 10,416	$ 9,391
Less: Total accumulated depreciation	(8,070)	(7,562)
Construction in progress		433
Total property, plant and equipment, net	2,346	2,262
Manufacturing equipment [Member]
Property, Plant and Equipment [Line Items]
Total cost	9,515	8,566
Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Total cost	458	410
Transportation Equipment [Member]
Property, Plant and Equipment [Line Items]
Total cost	200	191
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Total cost	$ 243	$ 224

Property, Plant and Equipment45

Property, Plant and Equipment, Net - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Property Plant And Equipment Capitalized Interest Costs [Abstract]
Depreciation expense	$ 55	$ 31	$ 162	$ 119

Short-Term Borrowing (Detail)

Short-Term Borrowing (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Short-term Debt [Line Items]
Short-term borrowings	$ 3,472	$ 4,761
Borrowings from Bank of China, due on February 10, 2017 with annual interest rate of 4.8%, secured by certain of the Company's intellectual property and fully repaid on February 13, 2017 [Member]
Short-term Debt [Line Items]
Short-term borrowings		1,222
Borrowings from Bank of Shanghai Pudong Branch, due on June 24, 2017 with an annual interest rate of 5.66%, guaranteed by the Company's CEO and fully repaid on June 25, 2017 [Member]
Short-term Debt [Line Items]
Short-term borrowings		281
Line of credit up to $3,605 from Bank of Shanghai Pudong Branch, due on July 3, 2017 with an annual interest rate of 5.66%, guaranteed by the Company's CEO and fully repaid on May 18, 2017 [Member]
Short-term Debt [Line Items]
Short-term borrowings		1,455
Line of credit up to $3,670 from Bank of Shanghai Pudong Branch, due on July 3, 2017 with an annual interest rate of 3.2%, guaranteed by the Company's CEO and fully repaid on June 7, 2017 [Member]
Short-term Debt [Line Items]
Short-term borrowings		$ 1,803
Line of credit up to $4,521 from Bank of China Pudong Branch, due on March 5, 2018 with annual interest rate of 5.69%, secured by certain of the Company's intellectual property [Member]
Short-term Debt [Line Items]
Short-term borrowings	2,185
Line of credit up to $3,767 from Bank of Shanghai Pudong Branch, due on September 22,2018 with an annual interest rate of 5.66%, guaranteed by the Company's CEO [Member]
Short-term Debt [Line Items]
Short-term borrowings	663
Line of credit up to $3,767 from Bank of Shanghai Pudong Branch, due on September 23,2018 with an annual interest rate of 5.66%, guaranteed by the Company's CEO [Member]
Short-term Debt [Line Items]
Short-term borrowings	$ 624

Short-Term Borrowing (Parenthet

Short-Term Borrowing (Parenthetical) (Detail) - USD ($)	9 Months Ended	12 Months Ended
Short-Term Borrowing (Parenthetical) (Detail) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Borrowings from Bank of China, due on February 10, 2017 with annual interest rate of 4.8%, secured by certain of the Company's intellectual property and fully repaid on February 13, 2017 [Member]
Short-term Debt [Line Items]
Maturity date		Feb. 10, 2017
Interest rate		4.80%
Repayment date		Feb. 13, 2017
Borrowings from Bank of Shanghai Pudong Branch, due on June 24, 2017 with an annual interest rate of 5.66%, guaranteed by the Company's CEO and fully repaid on June 25, 2017 [Member]
Short-term Debt [Line Items]
Maturity date		Jun. 24, 2017
Interest rate		5.66%
Repayment date		Jun. 25, 2017
Line of credit up to $3,605 from Bank of Shanghai Pudong Branch, due on July 3, 2017 with an annual interest rate of 5.66%, guaranteed by the Company's CEO and fully repaid on May 18, 2017 [Member]
Short-term Debt [Line Items]
Line of credit maximum borrowing capacity		$ 3,605,000
Maturity date		Jul. 3, 2017
Interest rate		5.66%
Repayment date		Jun. 7, 2017
Line of credit up to $3,670 from Bank of Shanghai Pudong Branch, due on July 3, 2017 with an annual interest rate of 3.2%, guaranteed by the Company's CEO and fully repaid on June 7, 2017 [Member]
Short-term Debt [Line Items]
Line of credit maximum borrowing capacity		$ 3,670,000
Maturity date		Jul. 3, 2017
Interest rate		3.20%
Repayment date		May 18, 2017
Line of credit up to $4,521 from Bank of China Pudong Branch, due on March 5, 2018 with annual interest rate of 5.69%, secured by certain of the Company's intellectual property [Member]
Short-term Debt [Line Items]
Line of credit maximum borrowing capacity	$ 4,521,000
Maturity date	Mar. 5, 2018
Interest rate	5.69%
Line of credit up to $3,767 from Bank of Shanghai Pudong Branch, due on September 22,2018 with an annual interest rate of 5.66%, guaranteed by the Company's CEO [Member]
Short-term Debt [Line Items]
Line of credit maximum borrowing capacity	$ 3,767,000
Maturity date	Sep. 22, 2018
Interest rate	5.66%
Line of credit up to $3,767 from Bank of Shanghai Pudong Branch, due on September 23,2018 with an annual interest rate of 5.66%, guaranteed by the Company's CEO [Member]
Short-term Debt [Line Items]
Line of credit maximum borrowing capacity	$ 3,767,000
Maturity date	Sep. 23, 2018
Interest rate	5.66%

Short-Term Borrowings - Additio

Short-Term Borrowings - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Debt Disclosure [Abstract]
Interest expense related to short-term borrowings	$ 33	$ 39	$ 196	$ 150

Other Payable and Accrued Exp49

Other Payable and Accrued Expenses (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Payables and Accruals [Abstract]
Lease expenses and payable for leasehold improvement due to a related party (note 12)	$ 2,024	$ 1,883
Commissions	688	757
Accrued warranty	529	290
Accrued payroll	2	398
Accrued professional fees	908	46
Accrued machine testing fee	405
Others	708	589
Total	$ 5,264	$ 3,963

Investors' Deposits - Additiona

Investors' Deposits - Additional Information (Detail) $ / shares in Units, ¥ in Thousands, $ in Thousands	Mar. 14, 2017USD ($)$ / sharesshares	Dec. 31, 2016USD ($)	Dec. 09, 2016CNY (¥)	Dec. 09, 2016USD ($)
Deposit Liabilities [Line Items]
Investors' deposit \| $		$ 2,902
Shengxin (Shanghai) Management Consulting Limited Partnership [Member]
Deposit Liabilities [Line Items]
Investors' deposit	$ 2,981		¥ 20,124	$ 2,981
Warrant exercisable to purchase shares of Class A common stock \| shares	397,502
warrant exercisable to purchase common stock price \| $ / shares	$ 7.50

Warrant Liability - Additional

Warrant Liability - Additional Information (Detail) $ / shares in Units, ¥ in Thousands, $ in Thousands	Mar. 14, 2017USD ($)$ / sharesshares	Dec. 31, 2016USD ($)	Dec. 09, 2016CNY (¥)	Dec. 09, 2016USD ($)
Class of Warrant or Right [Line Items]
Investors' deposit \| $		$ 2,902
Shengxin (Shanghai) Management Consulting Limited Partnership [Member]
Class of Warrant or Right [Line Items]
Warrant exercisable to purchase shares of Class A common stock \| shares	397,502
warrant exercisable to purchase common stock price \| $ / shares	$ 7.50
Warrant exercisable date	May 17, 2023
Equity interest percentage in satisfaction of SMC Investment if warrant not exercise	3.6394%
Investors' deposit	$ 2,981		¥ 20,124	$ 2,981
RMB-to-US dollar exchange rate	6.75

Black-Scholes Valuation Model A

Black-Scholes Valuation Model Assumptions Used to Value Warrant (Detail) - Warrant [Member]	9 Months Ended
	Sep. 30, 2017$ / shares
Class of Warrant or Right [Line Items]
Fair value of common share	$ 7.23	[1]
Expected term in years	5 years 7 months 17 days	[2]
Volatility	28.73%	[3]
Risk-free interest rate	1.92%	[4]
Expected dividend	0.00%	[5]

[1]	As the common stock was not publicly traded as of September 30. 2017, the Company used an independent third-party valuation firm to value the common stock price.
[2]	Expected term of the warrant represents the period from the current balance sheet date to the warrant expiration date.
[3]	Volatility is calculated based on the historical volatility of ACM's comparable companies in the period equal to the expected term of the warrant.
[4]	Risk-free interest rate is based on the yields of U.S. Treasury securities with maturities similar to the expected term of the warrant.
[5]	Expected dividend is assumed to be 0% as ACM has no history or expectation of paying a dividend on its common stock.

Black-Scholes Valuation Model53

Black-Scholes Valuation Model Assumptions Used to Value Warrant (Parenthetical) (Detail)	9 Months Ended
	Sep. 30, 2017
Warrant [Member]
Class of Warrant or Right [Line Items]
Expected dividend	0.00%	[1]

[1]	Expected dividend is assumed to be 0% as ACM has no history or expectation of paying a dividend on its common stock.

Other Long-Term Liabilities (De

Other Long-Term Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Other Long Term Liabilities [Line Items]
Other long-term liabilities	$ 6,682	$ 6,879
Subsidies to Stress Free Polishing project [Member]
Other Long Term Liabilities [Line Items]
Other long-term liabilities	1,930	1,958
Subsidies to Electro Copper Plating project [Member]
Other Long Term Liabilities [Line Items]
Other long-term liabilities	4,710	$ 4,921
Subsidies to Patent project [Member]
Other Long Term Liabilities [Line Items]
Other long-term liabilities	$ 42

Equity Method Investment - Addi

Equity Method Investment - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Sep. 11, 2017	Sep. 30, 2017
Post-closing equity purchase price		$ 1,200
Ninebell [Member]
Equity method investment percentage	20.00%
Post-closing equity purchase price	$ 1,200
Purchase price of equity method investment, shares issued	133,334
Purchase price of equity method investment	$ 1,000
Purchase price of equity method investment, per share	$ 7.50
Undistributed earnings attributable to ACM's equity method investment		$ 20

Related Party Balances and Tr56

Related Party Balances and Transactions - Additional Information (Detail) $ / shares in Units, ¥ in Thousands	Aug. 18, 2017USD ($)	Mar. 14, 2017USD ($)$ / shares	Sep. 30, 2017USD ($)	Sep. 30, 2016USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2016USD ($)	Dec. 31, 2016USD ($)	Dec. 09, 2016CNY (¥)	Dec. 09, 2016USD ($)	Dec. 31, 2007USD ($)
Related Party Transaction [Line Items]
Accounts payable-related party			$ 1,925,000		$ 1,925,000		$ 508,000
Investors' deposit							2,902,000
Ninebell [Member] \| Loan Agreement [Member]
Related Party Transaction [Line Items]
Interest-free loans	$ 946,000
Loan payable period	180 days
Purchased materials amount			807,000	$ 382,000	2,624,000	$ 1,446,000
Accounts payable-related party			1,925,000		1,925,000		508,000
Shanghai Zhangjiang Group Co., Ltd. [Member] \| Operating Lease Agreement [Member]
Related Party Transaction [Line Items]
Leasehold improvements										$ 771,000
Leasing expense under lease agreement			130,000	$ 451,000	161,000	$ 491,000
Lease expenses and payable for leasehold improvement due to a related party					2,024,000		1,883,000
Shengxin (Shanghai) Management Consulting Limited Partnership [Member]
Related Party Transaction [Line Items]
Investors' deposit		$ 2,981,000						¥ 20,124	$ 2,981,000
Stock issued, price per share \| $ / shares		$ 7.50
Exchange rate		6.75
Shengxin (Shanghai) Management Consulting Limited Partnership [Member] \| Class A Common Stock [Member]
Related Party Transaction [Line Items]
Stock issued, shares		$ 397,502
Stock issued, price per share \| $ / shares		$ 7.50
Total exercise price		$ 2,981,000
Shengxin (Shanghai) Management Consulting Limited Partnership [Member] \| ACM Shanghai [Member]
Related Party Transaction [Line Items]
Investors' deposit			$ 0		$ 0		$ 2,902,000
Equity interest percentage			3.6394%		3.6394%
Warrant obligation due to the inability of the parties to obtain required governmental or equity holder approvals					$ 2,981,000
Exchange rate			6.75		6.75

Leases - Additional Information

Leases - Additional Information (Detail) $ in Thousands	Mar. 22, 2017$ / ft²	Mar. 31, 2015ft²$ / ft²	Sep. 30, 2017USD ($)	Sep. 30, 2016USD ($)	Sep. 30, 2017USD ($)$ / ft²	Sep. 30, 2016USD ($)	Dec. 31, 2007ft²
Property Subject to or Available for Operating Lease [Line Items]
Rent expense					$ 473	$ 511
Rent expense			$ 140	$ 168	$ 476	$ 437
California [Member] \| Lease Agreements [Member]
Property Subject to or Available for Operating Lease [Line Items]
Lease agreement period		2 years
Area of property under lease agreement \| ft²		3,000
Rate per square feet \| $ / ft²	3	2
Lease agreement extended date					Extend the lease term through September 30, 2018
China [Member] \| ACM Wuxi [Member]
Property Subject to or Available for Operating Lease [Line Items]
Rate per square feet \| $ / ft²					1
China [Member] \| Operating Lease [Member] \| Shanghai Zhangjiang Group Co., Ltd. [Member] \| ACM Shanghai [Member]
Property Subject to or Available for Operating Lease [Line Items]
Area of property under lease agreement \| ft²							63,510
Rent expense					$ 58

Leases - Future Minimum Lease P

Leases - Future Minimum Lease Payments under Non-cancelable Lease Agreements (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Operating Leases, Future Minimum Payments Receivable [Abstract]
2,017	$ 2,193	$ 2,538
2,018	9	8
Total	$ 2,202	$ 2,546

Common Stock - Additional Infor

Common Stock - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Sep. 08, 2017	Sep. 30, 2017	Aug. 31, 2017	Dec. 31, 2016
Class of Stock [Line Items]
Stock conversion basis		Class B common stock is entitled to twenty votes and is convertible at any time into one share of Class A common stock
Shanghai Pudong High-Tech Investment Co., Ltd. [Member]
Class of Stock [Line Items]
Percentage of equity interest			10.78%
Zhangjiang Science and Technology Venture Capital Co Ltd [Member]
Class of Stock [Line Items]
Percentage of equity interest			7.58%
Class A Common Stock [Member]
Class of Stock [Line Items]
Common stock, shares authorized		100,000,000		100,000,000
Common stock, par value		$ 0.0001		$ 0.0001
Common stock, shares issued		4,741,635		2,228,740
Common stock, shares outstanding		4,741,635		2,228,740
Class A Common Stock [Member] \| Employee and Non-employee [Member]
Class of Stock [Line Items]
Common stock, shares issued		472,887
Class A Common Stock [Member] \| Ninebell [Member]
Class of Stock [Line Items]
Common stock, shares issued		133,334
Common stock issued price per share		$ 7.50
Aggregate stock purchase price		$ 1,000
Class A Common Stock [Member] \| Pudong Science and Technology (Cayman) Co., Ltd. [Member]
Class of Stock [Line Items]
Common stock, shares issued	1,119,576
Common stock issued price per share	$ 7.50
Aggregate stock purchase price	$ 8,397
Class A Common Stock [Member] \| Zhangjiang AJ Company Limited [Member]
Class of Stock [Line Items]
Common stock, shares issued	787,098
Common stock issued price per share	$ 7.50
Aggregate stock purchase price	$ 5,903
Common Class B [Member]
Class of Stock [Line Items]
Common stock, shares authorized		7,303,533		7,303,533
Common stock, par value		$ 0.0001		$ 0.0001
Common stock, shares issued		2,409,738		2,409,738
Common stock, shares outstanding		2,409,738		2,409,738

Redeemable Convertible Prefer60

Redeemable Convertible Preferred Stock - Additional Information (Detail) $ / shares in Units, ¥ in Thousands, $ in Thousands	1 Months Ended		9 Months Ended
	Mar. 31, 2017CNY (¥)	Mar. 31, 2017USD ($)shares	Sep. 30, 2017USD ($)$ / sharesshares	Dec. 31, 2016USD ($)shares
Temporary Equity [Line Items]
Redeemable preferred stock, shares authorized			22,696,467
Purchase of non-controlling interest \| $			$ 6,154
Series E convertible preferred stock purchase price \| $			$ 23,834	$ 18,034
Conversion of outstanding preferred stock, reserved for issuance			4,627,577	2,960,968
Shanghai Science and Technology Venture Capital Co Ltd [Member]
Temporary Equity [Line Items]
Purchase of non-controlling interest	¥ 40,000	$ 6,154
Series A Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Redeemable preferred stock, shares authorized			385,000	385,000
Redeemable preferred stock, shares issued			385,000	385,000
Series E convertible preferred stock purchase price \| $			$ 288	$ 288
Redeemable preferred stock, shares outstanding			385,000	385,000
Convertible preferred stock convertible into common stock			0.3333
Convertible preferred stock price per share \| $ / shares			$ 0.80
Series B Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Redeemable preferred stock, shares authorized			1,572,000	1,572,000
Redeemable preferred stock, shares issued			1,572,000	1,572,000
Series E convertible preferred stock purchase price \| $			$ 1,572	$ 1,572
Redeemable preferred stock, shares outstanding			1,572,000	1,572,000
Convertible preferred stock convertible into common stock			0.3333
Convertible preferred stock price per share \| $ / shares			$ 1
Series C Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Redeemable preferred stock, shares authorized			1,360,962	1,360,962
Redeemable preferred stock, shares issued			1,360,962	1,360,962
Series E convertible preferred stock purchase price \| $			$ 2,041	$ 2,041
Redeemable preferred stock, shares outstanding			1,360,962	1,360,962
Convertible preferred stock convertible into common stock			0.3544
Convertible preferred stock price per share \| $ / shares			$ 1.50
Series D Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Redeemable preferred stock, shares authorized			2,659,975	2,659,975
Redeemable preferred stock, shares issued			1,326,642	1,326,642
Series E convertible preferred stock purchase price \| $			$ 4,975	$ 4,975
Redeemable preferred stock, shares outstanding			1,326,642	1,326,642
Convertible preferred stock convertible into common stock			0.4562
Convertible preferred stock price per share \| $ / shares			$ 3.75
Series E Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Redeemable preferred stock, shares authorized			10,718,530	10,718,530
Redeemable preferred stock, shares issued			4,998,508	0
Series E convertible preferred stock purchase price \| $			$ 5,800
Redeemable preferred stock, shares outstanding			4,998,508	0
Convertible preferred stock convertible into common stock			0.3333
Convertible preferred stock price per share \| $ / shares			$ 1
Series E Convertible Preferred Stock [Member] \| Shanghai Science and Technology Venture Capital Co Ltd [Member]
Temporary Equity [Line Items]
Redeemable preferred stock, shares issued		4,998,508
Series E convertible preferred stock purchase price \| $		$ 5,800
Series F Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Redeemable preferred stock, shares authorized			6,000,000	6,000,000
Redeemable preferred stock, shares issued			3,663,254	3,663,254
Series E convertible preferred stock purchase price \| $			$ 9,158	$ 9,158
Redeemable preferred stock, shares outstanding			3,663,254	3,663,254
Convertible preferred stock convertible into common stock			0.3333
Convertible preferred stock price per share \| $ / shares			$ 2.50
Class A Common Stock [Member]
Temporary Equity [Line Items]
Aggregate proceeds from initial public offering of common stock \| $			$ 20,000
Common stock per share price \| $ / shares			$ 15

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Employee Share Option Activities (Detail) - Employee Awards [Member] - $ / shares	9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Option Shares, Outstanding, Beginning balance	2,100,377
Number of Option Shares, Outstanding, Granted	83,334	0
Number of Option Shares, Outstanding, Exercised	(174,334)
Number of Option Shares, Outstanding, Expired	(903)
Number of Option Shares, Outstanding, Forfeited	(12,584)
Number of Option Shares, Outstanding, Ending balance	1,995,890		2,100,377
Vested and exercisable at September 30, 2017	902,821
Weighted Average Grant Date Fair Value, Outstanding, Beginning balance	$ 0.54
Weighted Average Grant Date Fair Value, Granted	2.58
Weighted Average Grant Date Fair Value, Exercised	0.45
Weighted Average Grant Date Fair Value, Expired	0.55
Weighted Average Grant Date Fair Value, Forfeited	0.54
Weighted Average Grant Date Fair Value, Outstanding, Ending balance	0.63		$ 0.54
Weighted Average Exercise Price, Outstanding, Beginning balance	2.03
Weighted Average Exercise Price, Granted	7.50
Weighted Average Exercise Price, Exercised	0.75
Weighted Average Exercise Price, Expired	3
Weighted Average Exercise Price, Forfeited	3
Weighted Average Exercise Price, Outstanding, Ending balance	$ 2.37		$ 2.03
Weighted Average Remaining Contractual Term, Outstanding	7 years 9 months 7 days		7 years 9 months 29 days

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Employee Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 72	$ 22	$ 200	$ 68
Unrecognized employee stock-based compensation expense, net of estimated forfeitures	712		$ 712		$ 726
weighted-average period over which unrecognized compensation is expected to be recognized			1 year 11 months 1 day		2 years 3 months
Number of options granted			83,334	0
Non-employee Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 272	$ (23)	$ 1,492	$ 125
Number of options granted			133,335	0

Stock-Based Compensation - Su63

Stock-Based Compensation - Summary of Assumptions used to Determine Fair Value of Employee Share Options Granted (Detail) - Employee Awards [Member]	9 Months Ended
	Sep. 30, 2017$ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of common share	$ 7.59	[1]
Expected term in years	6 years 3 months	[2]
Volatility	29.18%	[3]
Risk-free interest rate	2.22%	[4]
Expected dividend	0.00%	[5]

[1]	As the common stock was not publicly traded, the Company used an independent third-party valuation firm to value the common stock.
[2]	Expected term of share options is based on the average of the vesting period and the contractual term for each grant according to Staff Accounting Bulletin 110.
[3]	Volatility is calculated based on the historical volatility of ACM's comparable companies in the period equal to the expected term of each grant.
[4]	Risk-free interest rate is based on the yields of U.S. Treasury securities with maturities similar to the expected term of the share options in effect at the time of grant.
[5]	Expected dividend is assumed to be 0% as ACM has no history or expectation of paying a dividend on its common stock.

Stock-Based Compensation - Su64

Stock-Based Compensation - Summary of Assumptions used to Determine Fair Value of Employee Share Options Granted (Parenthetical) (Detail)	9 Months Ended
	Sep. 30, 2017
Employee Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend	0.00%	[1]

[1]	Expected dividend is assumed to be 0% as ACM has no history or expectation of paying a dividend on its common stock.

Stock-Based Compensation - Su65

Stock-Based Compensation - Summary of Non-employee Share Option Activities (Detail) - Non-employee Awards [Member] - $ / shares	9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Option Shares, Outstanding, Beginning balance	1,578,565
Number of Option Shares, Outstanding, Granted	133,335	0
Number of Option Shares, Outstanding, Exercised	(298,555)
Number of Option Shares, Outstanding, Expired	(133,336)
Number of Option Shares, Outstanding, Ending balance	1,280,009		1,578,565
Vested and exercisable at September 30, 2017	686,875
Weighted Average Grant Date Fair Value, Outstanding, Beginning balance	$ 0.51
Weighted Average Grant Date Fair Value, Granted	2.46
Weighted Average Grant Date Fair Value, Exercised	0.39
Weighted Average Grant Date Fair Value, Expired	0.45
Weighted Average Grant Date Fair Value, Outstanding, Ending balance	0.75		$ 0.51
Weighted Average Exercise Price, Outstanding, Beginning balance	1.58
Weighted Average Exercise Price, Granted	7.50
Weighted Average Exercise Price, Exercised	0.93
Weighted Average Exercise Price, Expired	0.75
Weighted Average Exercise Price, Outstanding, Ending balance	$ 2.43		$ 1.58
Weighted Average Remaining Contractual Term, Outstanding	7 years 8 months 12 days		6 years 9 months 22 days

Stock-Based Compensation - Su66

Stock-Based Compensation - Summary of Assumptions used to Determine Fair Value of Non-employee Share Options Granted (Detail) - Non-employee Awards [Member]	9 Months Ended
	Sep. 30, 2017$ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term in years	6 years 3 months	[1]
Volatility, minimum	29.18%	[2]
Volatility, maximum	29.51%	[2]
Risk-free interest rate, minimum	2.22%	[3]
Risk-free interest rate, maximum	2.43%	[3]
Expected dividend	0.00%	[4]
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of common share	$ 6.87	[5]
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of common share	$ 7.59	[5]

[1]	Expected term of share options is based on the average of the vesting period and the contractual term for each grant according to Staff Accounting Bulletin 110
[2]	Volatility is calculated based on the historical volatility of ACM's comparable companies in the period equal to the expected term of each grant.
[3]	Risk-free interest rate is based on the yields of U.S. Treasury securities with maturities similar to the expected term of the share options in effect at the time of grant.
[4]	Expected dividend is assumed to be 0% as ACM has no history or expectation of paying a dividend on its common stock.
[5]	As the common stock was not publicly traded, the Company used an independent third-party valuation firm to value the common stock.

Stock-Based Compensation - Su67

Stock-Based Compensation - Summary of Assumptions used to Determine Fair Value of Non-employee Share Options Granted (Parenthetical) (Detail)	9 Months Ended
	Sep. 30, 2017
Non-employee Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend	0.00%	[1]

[1]	Expected dividend is assumed to be 0% as ACM has no history or expectation of paying a dividend on its common stock.

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
Income Taxes - Additional Information (Detail) - USD ($)	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Taxes [Line Items]
Statutory U.S federal income tax rate			34.00%
Income tax provision (benefit)	$ (278,000)	$ 132,000	$ 471,000	$ 59,000
Unrecognized tax benefits	$ 44,000		44,000
Interest or penalties related to unrecognized tax benefits			$ 0
Earliest Tax Year [Member]
Income Taxes [Line Items]
Open tax year			2,009
Latest Tax Year [Member]
Income Taxes [Line Items]
Open tax year			2,016
Minimum [Member]
Income Taxes [Line Items]
Statutory Chinese income tax rate			15.00%
Maximum [Member]
Income Taxes [Line Items]
Statutory Chinese income tax rate			25.00%

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Commitments And Contingencies [Line Items]
Rental expenses	$ 473	$ 511
Minimum [Member]
Commitments And Contingencies [Line Items]
Lease, term of contract	1 year

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	Nov. 14, 2017	Nov. 07, 2017	Nov. 30, 2017	Sep. 30, 2017	Dec. 31, 2016
Class A Common Stock [Member]
Subsequent Event [Line Items]
Common stock, shares authorized				100,000,000	100,000,000
Common stock, par value per share				$ 0.0001	$ 0.0001
Common Class B [Member]
Subsequent Event [Line Items]
Common stock, shares authorized				7,303,533	7,303,533
Common stock, par value per share				$ 0.0001	$ 0.0001
Subsequent Event [Member]
Subsequent Event [Line Items]
Preferred stock, shares authorized			10,000,000
Preferred stock, par value per share			$ 0.0001
Subsequent Event [Member] \| Class A Common Stock [Member]
Subsequent Event [Line Items]
Shares issued and sold	3,566,334
Stock price	$ 5.60
Aggregate gross proceeds	$ 20
Net proceeds after deducting underwriting discounts and commissions, placement fees, and offering costs	$ 16.5
Number of shares converted		4,627,577
Common stock, shares authorized			50,000,000
Common stock, par value per share			$ 0.0001
Subsequent Event [Member] \| Common Class B [Member]
Subsequent Event [Line Items]
Common stock, shares authorized			2,409,738
Common stock, par value per share			$ 0.0001
Subsequent Event [Member] \| IPO [Member] \| Class A Common Stock [Member]
Subsequent Event [Line Items]
Shares issued and sold		2,000,000	2,233,000
Subsequent Event [Member] \| Over-Allotment Option [Member] \| Class A Common Stock [Member]
Subsequent Event [Line Items]
Shares issued and sold	233,000
Subsequent Event [Member] \| Private Placement [Member] \| Class A Common Stock [Member]
Subsequent Event [Line Items]
Shares issued and sold			1,333,334