SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Equity Securities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Debt and Equity Securities, FV-NI [Line Items]
Cost	$ 59,157		$ 63,383
Gross Unrealized Gain	17,922	$ 14,819
Gross Unrealized Loss	(16,355)	(16,594)
Fair Value	60,724		61,608
Equity securities - Life Sciences Portfolio
Debt and Equity Securities, FV-NI [Line Items]
Cost	28,498		28,498
Gross Unrealized Gain	15,337	14,815
Gross Unrealized Loss	(562)	(617)
Fair Value	43,273		42,696
Equity securities - other common stock
Debt and Equity Securities, FV-NI [Line Items]
Cost	30,659		34,885
Gross Unrealized Gain	2,585	4
Gross Unrealized Loss	(15,793)	$ (15,977)
Fair Value	$ 17,451		$ 18,912