SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Disaggregation of Revenue [Line Items]
Total revenues	$ 16,717	$ 17,400	$ 30,224	$ 23,203
Intellectual property operations
Disaggregation of Revenue [Line Items]
Total revenues	8,062	17,400	10,677	23,203
Paid-up license revenue agreements
Disaggregation of Revenue [Line Items]
Total revenues	7,360	16,600	9,553	22,010
Recurring License Revenue Agreements
Disaggregation of Revenue [Line Items]
Total revenues	702	800	1,124	1,193
Industrial operations
Disaggregation of Revenue [Line Items]
Total revenues	8,655	$ 0	19,547	$ 0
Printers, consumables and parts
Disaggregation of Revenue [Line Items]
Total revenues	7,876		17,514
Services
Disaggregation of Revenue [Line Items]
Total revenues	$ 779		$ 2,033