Consolidated Entities - ISP Fund LP (Details) - USD ($) $ in Thousands		3 Months Ended
	Mar. 30, 2022	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	May 31, 2021	Dec. 31, 2020
CONSOLIDATED ENTITIES
Total assets		$ 1,107,474		$ 926,395
Changes in fair values of equity and long-term investments		$ (9,411)	$ 55,045
ISP Fund LP
CONSOLIDATED ENTITIES
Contributed to partnership for investing						$ 300,000
Distribution from partnership					$ 110,000
Economic interest of the Partnership (in percent)		100.00%
Total assets		$ 307,600		195,800
Total liabilities		100		$ 200
Investment-related expenses, net of investment-related income		300	400
Changes in fair values of equity and long-term investments		$ 2,100	$ 5,800
Commitment for future contribution	$ 110,000
Lock-up period	36 months