INVESTMENTS - (Net Unrealized Gains (Losses) Still Held (Details) - Equity securities - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Schedule of Investments [Line Items]
Net gains (losses) on equity securities: Realized	$ 0	$ 4,555	$ 803
Net gains (losses) on equity securities: Unrealized	3	(4,114)	4,116
Net gains (losses) on equity securities:	3	441	4,919
Less: Net realized and unrealized gains (losses) on securities sold	0	309	672
Net unrealized gains (losses) still held as of the end-of-period	$ 3	$ 132	$ 4,247