OTHER COMPREHENSIVE INCOME (LOSS) - Tax Effects of Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Before tax amount
Unrealized gains (losses) arising during the period, net of reclassification adjustment	$ (72,887)	$ (390,651)	$ 140,034	$ (845,936)
Foreign currency translation adjustment	3,183	(6,193)	2,648	(3,418)
Total comprehensive income (loss), before tax	(69,704)	(396,844)	142,682	(849,354)
Income tax (expense) benefit
Unrealized gains (losses) arising during the period, net of reclassification adjustment	11,091	11,030	(12,891)	68,704
Foreign currency translation adjustment	0	0	0	0
Total comprehensive income (loss), net of tax	11,091	11,030	(12,891)	68,704
Net of tax amount
Unrealized gains (losses) arising during the period, net of reclassification adjustment	(61,796)	(379,621)	127,143	(777,232)
Foreign currency translation adjustment	3,183	(6,193)	2,648	(3,418)
Total other comprehensive income (loss), net of tax	(58,613)	(385,814)	129,791	(780,650)
Available for sale investments
Before tax amount
Adjustment for reclassification of net realized (gains) losses and impairment losses recognized in net income (loss)	40,157	93,813	84,277	146,729
Income tax (expense) benefit
Adjustment for reclassification of net realized (gains) losses and impairment losses recognized in net income (loss)	(3,536)	(9,449)	(6,907)	(17,023)
Net of tax amount
Adjustment for reclassification of net realized (gains) losses and impairment losses recognized in net income (loss)	36,621	84,364	77,370	129,706
Unrealized gains (losses) arising during the period, net of reclassification adjustment	(61,796)	(379,621)	127,143	(777,232)
Available for sale investments | Unrealized gains (losses) arising during the period for which an allowance for expected credit losses has been recognized
Before tax amount
Unrealized gains (losses) arising during the period	(112,993)	(482,284)	46,744	(987,265)
Income tax (expense) benefit
Unrealized gains (losses) arising during the period	14,591	20,338	(5,044)	85,494
Net of tax amount
Unrealized gains (losses) arising during the period	(98,402)	(461,946)	41,700	(901,771)
Available for sale investments | Unrealized gains (losses) arising during the period for which an allowance for expected credit losses has not been recognized
Before tax amount
Unrealized gains (losses) arising during the period	(51)	(2,180)	9,013	(5,400)
Income tax (expense) benefit
Unrealized gains (losses) arising during the period	36	141	(940)	233
Net of tax amount
Unrealized gains (losses) arising during the period	$ (15)	$ (2,039)	$ 8,073	$ (5,167)