REVENUE RECOGNITION - Disaggregated Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Disaggregation of Revenue [Line Items]
Total revenues	$ 9,482	$ 14,006	$ 23,539	$ 29,297
Total royalty and license revenue
Disaggregation of Revenue [Line Items]
Total revenues	9,474	13,931	23,401	29,079
Fixed fee license revenue
Disaggregation of Revenue [Line Items]
Total revenues	1,191	7,662	3,594	10,653
Per-unit royalty revenue
Disaggregation of Revenue [Line Items]
Total revenues	8,283	6,269	19,807	18,426
Development, services, and other revenue
Disaggregation of Revenue [Line Items]
Total revenues	$ 8	$ 75	$ 138	$ 218