INVESTMENTS (Net Realized Gains (Losses) by Major Investment Category (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Gross realized and unrealized gains:
Total gross realized and unrealized gains	$ 416	$ 11,289	$ 1,281	$ 12,994
Gross realized and unrealized losses:
Total gross realized and unrealized losses	(257)	(906)	(1,030)	(5,436)
Net realized and unrealized gains (losses) on investments	159	10,383	251	7,558
Debt Securities
Gross realized and unrealized gains:
Debt securities	304	9,403	1,168	10,789
Gross realized and unrealized losses:
Debt securities	(302)	(2,339)	(1,022)	(2,487)
Equity Securities
Gross realized and unrealized gains:
Equity securities	112	1,886	113	2,205
Gross realized and unrealized losses:
Equity securities	$ 45	$ 1,433	$ (8)	$ (2,949)