CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Statement of Comprehensive Income [Abstract]
Net income, before-tax amount	$ 262,626	$ 240,708	$ 704,272	$ 719,975
Net income, tax	(59,582)	(53,935)	(152,140)	(159,910)
Net income	203,044	186,773	552,132	560,065
Before-tax Amount
Net unrealized gains (losses) arising during the period	(565,121)	(55,472)	(1,616,011)	(174,371)
Reclassification adjustment for realized (gains) losses included in net income	0	(962)	0	1,028
Net change	(565,121)	(56,434)	(1,616,011)	(173,343)
Income Tax
Net unrealized gains (losses) arising during the period	134,668	14,035	384,019	45,091
Reclassification adjustment for realized (gains) losses included in net income	0	243	0	(272)
Net change	134,668	14,278	384,019	44,819
Net of Tax Amount
Net unrealized gains (losses) arising during the period	(430,453)	(41,437)	(1,231,992)	(129,280)
Reclassification adjustment for realized (gains) losses included in net income	0	(719)	0	756
Net change	(430,453)	(42,156)	(1,231,992)	(128,524)
Before-tax Amount
Net unrealized gains (losses) arising during the period	(111,549)	(8,081)	(284,216)	(39,061)
Reclassification adjustment for realized (gains) losses included in net income	10,253	(4,009)	(4,556)	(9,265)
Net change	(101,296)	(12,090)	(288,772)	(48,326)
Income Tax
Net unrealized gains (losses) arising during the period	26,582	2,044	67,685	10,404
Reclassification adjustment for realized (gains) losses included in net income	(2,442)	1,014	1,086	2,349
Net change	24,140	3,058	68,771	12,753
Net of Tax Amount
Net unrealized gains (losses) arising during the period	(84,967)	(6,037)	(216,531)	(28,657)
Reclassification adjustment for realized (gains) losses included in net income	7,811	(2,995)	(3,470)	(6,916)
Net change	(77,156)	(9,032)	(220,001)	(35,573)
Total other comprehensive income (loss)	(666,417)	(68,524)	(1,904,783)	(221,669)
Other comprehensive income (loss), income tax	158,808	17,336	452,790	57,572
Total other comprehensive income (loss), net of tax	(507,609)	(51,188)	(1,451,993)	(164,097)
Comprehensive income (loss)	$ (304,565)	$ 135,585	$ (899,861)	$ 395,968