CONSOLIDATED ENTITIES - ISP Fund LP (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	May 31, 2021
CONSOLIDATED ENTITIES
Initial contribution	$ 66,278	$ 87,981	$ 0
Total assets	926,395	999,570
Unrealized loss on equity investments	89,309	50,277	0
Realized gain on equity investments	91,030	50,277	$ 0
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	195,800	$ 299,300
Investment-related expenses, net of investment-related income	3,600	400
Unrealized loss on equity investments	2,400	400
Payment for management and annual performance incentive fees	$ 3,100	$ 200
Lock-up period	36 months
Investment Income, Interest and Dividend	$ 1,800
Realized gain on equity investments	$ 10,500