SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Intellectual Property Operations (Details) - Intellectual property operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Inventor royalties	$ 1,142	$ 7,349
Contingent legal fees	12,074	7,419
Litigation and licensing expenses	5,462	5,683
Amortization of patents	9,851	4,681
Other patent portfolio expense (income)	162	(308)
Total cost of revenues	$ 28,691	$ 24,824