INCOME TAXES - Schedule of Loss Before Income Taxes by Source (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
U.S.	$ (45,327)	$ (222,484)
Outside the U.S.	(186)	0
Net loss before income taxes	$ (45,513)	$ (222,484)