SEGMENT REPORTING - Segment income and expense (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended	9 Months Ended	12 Months Ended
	Mar. 31, 2021	Jun. 30, 2021	Sep. 30, 2021	Dec. 31, 2021	Dec. 31, 2020
Revenues:
Revenues				$ 88,047	$ 29,782
Other operating expenses:
Engineering and development expenses - industrial operations				200	0
Sales and marketing expenses - industrial operations				1,538	0
Amortization of intangible assets				10,300	4,700
General and administrative expenses				35,666	24,476
Operating income (loss)				14,545	(19,518)
Total other income (expense)	$ (157,879)	$ (139,347)	$ (36,857)	160,107	127,590
Income before income taxes				174,652	108,072
Parent Company
Other operating expenses:
General and administrative expenses				26,692	19,500
Intellectual property operations
Revenues:
Revenues				76,043
Intellectual property operations | Parent Company
Other operating expenses:
General and administrative expenses					$ 5,000
Industrial operations
Revenues:
Revenues				12,004
Operating Segments
Revenues:
Revenues				88,047
Cost of revenues:
Inventor royalties				1,142
Contingent legal fees				12,074
Litigation and licensing expenses				5,462
Amortization of patents				9,851
Other patent portfolio expense (income)				162
Cost of sales				7,407
Total cost of revenues				36,098
Segment gross profit				51,949
Other operating expenses:
Engineering and development expenses - industrial operations				200
Sales and marketing expenses - industrial operations				1,538
Amortization of intangible assets				399
General and administrative expenses				8,575
Total other operating expenses				10,712
Operating income (loss)				41,237
Operating Segments | License fees
Revenues:
Revenues				76,043
Operating Segments | Printers and parts
Revenues:
Revenues				4,961
Operating Segments | Consumable products
Revenues:
Revenues				5,973
Operating Segments | Services
Revenues:
Revenues				1,070
Operating Segments | Intellectual property operations
Revenues:
Revenues				76,043
Cost of revenues:
Inventor royalties				1,142
Contingent legal fees				12,074
Litigation and licensing expenses				5,462
Amortization of patents				9,851
Other patent portfolio expense (income)				162
Cost of sales				0
Total cost of revenues				28,691
Segment gross profit				47,352
Other operating expenses:
Engineering and development expenses - industrial operations				0
Sales and marketing expenses - industrial operations				0
Amortization of intangible assets				0
General and administrative expenses				6,177
Total other operating expenses				6,177
Operating income (loss)				41,175
Operating Segments | Intellectual property operations | License fees
Revenues:
Revenues				76,043
Operating Segments | Intellectual property operations | Printers and parts
Revenues:
Revenues				0
Operating Segments | Intellectual property operations | Consumable products
Revenues:
Revenues				0
Operating Segments | Intellectual property operations | Services
Revenues:
Revenues				0
Operating Segments | Industrial operations
Revenues:
Revenues				12,004
Cost of revenues:
Inventor royalties				0
Contingent legal fees				0
Litigation and licensing expenses				0
Amortization of patents				0
Other patent portfolio expense (income)				0
Cost of sales				7,407
Total cost of revenues				7,407
Segment gross profit				4,597
Other operating expenses:
Engineering and development expenses - industrial operations				200
Sales and marketing expenses - industrial operations				1,538
Amortization of intangible assets				399
General and administrative expenses				2,398
Total other operating expenses				4,535
Operating income (loss)				62
Operating Segments | Industrial operations | License fees
Revenues:
Revenues				0
Operating Segments | Industrial operations | Printers and parts
Revenues:
Revenues				4,961
Operating Segments | Industrial operations | Consumable products
Revenues:
Revenues				5,973
Operating Segments | Industrial operations | Services
Revenues:
Revenues				$ 1,070