REVENUE FROM CONTRACTS WITH CUSTOMERS - Disaggregated Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Disaggregated Revenue Information [Abstract]
Revenue (note 3)	$ 168,569	$ 133,709	$ 387,402	$ 280,290
Mainland China
Disaggregated Revenue Information [Abstract]
Revenue (note 3)	168,302	131,180	375,528	273,585
Other regions
Disaggregated Revenue Information [Abstract]
Revenue (note 3)	267	2,529	11,874	6,705
Single wafer cleaning, Tahoe and semi-critical cleaning equipment
Disaggregated Revenue Information [Abstract]
Revenue (note 3)	132,417	99,720	281,559	198,336
ECP (front-end and packaging), furnace and other technologies
Disaggregated Revenue Information [Abstract]
Revenue (note 3)	25,508	24,521	71,223	57,269
Advanced packaging (excluding ECP), services & spares
Disaggregated Revenue Information [Abstract]
Revenue (note 3)	$ 10,644	$ 9,468	$ 34,620	$ 24,685