BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES - Cash and Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash and cash equivalents	$ 155,481	$ 56,547
Restricted cash	0	1,550
Total cash, cash equivalents, and restricted cash	$ 155,481	$ 58,097	$ 12,805	$ 8,223