DESCRIPTION OF BUSINESS - Narrative (Details) $ / shares in Units, $ in Thousands				6 Months Ended
	May 15, 2026 USD ($) $ / shares shares	May 12, 2026 shares	Feb. 06, 2026 USD ($) shares	Jun. 30, 2026 USD ($)	Jun. 30, 2025 USD ($)	Mar. 31, 2026	Feb. 06, 2026 ¥ / shares	Feb. 06, 2026 $ / shares	Dec. 31, 2025
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of shares issued in transaction (in shares) | shares	2,900,000
Sale of stock, price per share (in USD per share) | $ / shares	$ 52.00
Gross proceeds from sales of ACM Shanghai shares				$ 110,243	$ 0
Net proceeds received on sale of stock	$ 148,400
ACM Shanghai
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of shares issued in transaction (in shares) | shares			4,800,000
Sale of stock, price per share (in USD per share) | (per share)							¥ 160.00	$ 23.05
Gross proceeds from sales of ACM Shanghai shares			$ 110,200
Payments for (proceeds from) businesses and interest in affiliates, financing activities, net of tax			$ 86,000
Exercise of stock options (in shares) | shares		2,431,900
Effective interest held as at				73.20%		73.60%			74.60%
ACM Research (Chengdu), Inc. ("ACM Chengdu")
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Effective interest held as at				73.20%					74.60%