SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Cash and Cash Equivalents, at Carrying Value [Abstract]
Cash, cash equivalents and restricted cash and time deposits	$ 257,420		$ 257,420		$ 247,951
Short-term and long-term time deposits	118,104		118,104		172,448
ACM Shanghai
Cash and Cash Equivalents, at Carrying Value [Abstract]
Cash payments for procurement of goods and services	14,500	$ 5,647	25,431	$ 13,561
United States
Cash and Cash Equivalents, at Carrying Value [Abstract]
Cash, cash equivalents and restricted cash and time deposits	23,732		23,732		25,011
Mainland China
Cash and Cash Equivalents, at Carrying Value [Abstract]
Cash, cash equivalents and restricted cash and time deposits	123,071		123,071		129,695
China Hong Kong
Cash and Cash Equivalents, at Carrying Value [Abstract]
Cash, cash equivalents and restricted cash and time deposits	107,459		107,459		89,187
South Korea
Cash and Cash Equivalents, at Carrying Value [Abstract]
Cash, cash equivalents and restricted cash and time deposits	3,107		3,107		4,007
Singapore
Cash and Cash Equivalents, at Carrying Value [Abstract]
Cash, cash equivalents and restricted cash and time deposits	$ 51		$ 51		$ 51