Total number of shares cancelled after taking ownership.

No definition available.

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Balance Type:	na
Period Type:	duration

- Definition

Number of share warrants (or share units) exercised during the current period.

+ References

No definition available.

+ Details

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- Definition

Number of votes entitled for each share of common stock.

+ References

No definition available.

+ Details

Name:	acmr_VotingRightsPerShare
Namespace Prefix:	acmr_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- References

No definition available.

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- Definition

Face amount or stated value per share of common stock.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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- Definition

The maximum number of common shares permitted to be issued by an entity's charter and bylaws.

+ References

+ Details

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- Definition

Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

+ References

+ Details

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Data Type:	xbrli:sharesItemType
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Period Type:	instant

- Definition

Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

The number of shares converted in a noncash (or part noncash) transaction. Noncash is defined as transactions during a period that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 4
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Data Type:	xbrli:sharesItemType
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- Definition

Number of share options (or share units) exercised during the current period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(2)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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-Topic 505
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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Data Type:	xbrli:sharesItemType
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Period Type:	duration

- Definition

Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
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COMMON STOCK (Details)	1 Months Ended		3 Months Ended		9 Months Ended
COMMON STOCK (Details)	Apr. 30, 2020 shares	Aug. 31, 2019 shares	Sep. 30, 2020 Vote $ / shares shares	Sep. 30, 2019 shares	Sep. 30, 2020 Vote $ / shares shares	Sep. 30, 2019 shares	Dec. 31, 2019 $ / shares shares
Class of Stock [Abstract]
Number of shares cancelled (in shares)			242,681		242,681
SMC [Member]
Class of Stock [Abstract]
Share cancellation (in shares)	242,681	154,821
Common Class A [Member]
Class of Stock [Abstract]
Common stock, shares authorized (in shares)			50,000,000		50,000,000		50,000,000
Common stock, par value (in dollars per share) \| $ / shares			$ 0.0001		$ 0.0001		$ 0.0001
Number of votes for each share entitled \| Vote			1		1
Common stock, shares issued (in shares)			16,657,135		16,657,135		16,182,151
Common stock, shares outstanding (in shares)			16,657,135		16,657,135		16,182,151
Common Class A [Member] \| SMC [Member]
Class of Stock [Abstract]
Share cancellation (in shares)			242,681		242,681
Common Class A [Member] \| Common Stock [Member]
Class of Stock [Abstract]
Exercise of common stock warrant issued (in shares)					64,717
Stock issued upon exercise of stock options (in shares)			407,043	89,015	592,946	193,642
Share cancellation (in shares)				214,286	242,681	214,286
Common Class B [Member]
Class of Stock [Abstract]
Common stock, shares authorized (in shares)			2,409,738		2,409,738		2,409,738
Common stock, par value (in dollars per share) \| $ / shares			$ 0.0001		$ 0.0001		$ 0.0001
Number of votes for each share entitled \| Vote			20		20
Convertible shares in to Class A common stock (in shares)					1
Common stock, shares issued (in shares)			1,802,606		1,802,606		1,862,608
Common stock, shares outstanding (in shares)			1,802,606		1,802,606		1,862,608
Common Class B [Member] \| Common Stock [Member]
Class of Stock [Abstract]
Exercise of common stock warrant issued (in shares)					0
Stock issued upon exercise of stock options (in shares)			0	0	0	0
Share cancellation (in shares)				0	0	0