OTHER COMPREHENSIVE INCOME (LOSS) - Tax Effects of Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Before tax amount
Unrealized gains (losses) arising during the period, net of reclassification adjustment	$ (157,943)	$ (296,487)	$ (17,909)	$ (1,142,423)
Foreign currency translation adjustment	(6,950)	(12,751)	(4,302)	(16,169)
Total other comprehensive income (loss), before tax	(164,893)	(309,238)	(22,211)	(1,158,592)
Income tax (expense) benefit
Unrealized gains (losses) arising during the period, net of reclassification adjustment	19,963	(9,298)	7,072	59,406
Foreign currency translation adjustment	0	0	0	0
Income tax (expense) benefit	19,963	(9,298)	7,072	59,406
Net of tax amount
Unrealized gains (losses) arising during the period, net of reclassification adjustment	(137,980)	(305,785)	(10,837)	(1,083,017)
Foreign currency translation adjustment	(6,950)	(12,751)	(4,302)	(16,169)
Total other comprehensive income (loss), net of tax	(144,930)	(318,536)	(15,139)	(1,099,186)
Available for sale investments
Before tax amount
Adjustment for reclassification of net realized (gains) losses and impairment losses recognized in net income (loss)	26,241	108,351	110,518	255,081
Income tax (expense) benefit
Adjustment for reclassification of net realized (gains) losses and impairment losses recognized in net income (loss)	(3,223)	(9,572)	(10,130)	(25,308)
Net of tax amount
Adjustment for reclassification of net realized (gains) losses and impairment losses recognized in net income (loss)	23,018	98,779	100,388	229,773
Unrealized gains (losses) arising during the period, net of reclassification adjustment	(137,980)	(305,785)	(10,837)	(1,083,017)
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	(178,537)	(393,848)	(126,805)	(1,340,927)
Income tax (expense) benefit
Unrealized gains (losses) arising during the period	22,486	(32)	17,210	81,445
Net of tax amount
Unrealized gains (losses) arising during the period	(156,051)	(393,880)	(109,595)	(1,259,482)
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	(5,647)	(10,990)	(1,622)	(56,577)
Income tax (expense) benefit
Unrealized gains (losses) arising during the period	700	306	(8)	3,269
Net of tax amount
Unrealized gains (losses) arising during the period	$ (4,947)	$ (10,684)	$ (1,630)	$ (53,308)