Supplemental Information about Changes to Accumulated Other Comprehensive Income - Schedule of Change in Balance by Component (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Increase (Decrease) in AOCI, Net of Tax
Beginning balance	$ 8,642,806	$ 8,771,092	$ 7,294,307
Other comprehensive income (loss) before reclassifications, net of tax	(4,129,740)	(343,041)	1,145,356
Reclassifications, net of tax	36,443	(8,620)	39,058
Other comprehensive income (loss)	(4,093,297)	(351,661)	1,184,414
Ending balance	4,895,861	8,642,806	8,771,092
Total
Increase (Decrease) in AOCI, Net of Tax
Beginning balance	2,677,583	3,029,244	1,844,830
Ending balance	(1,415,714)	2,677,583	3,029,244
Available for Sale Assets
Increase (Decrease) in AOCI, Net of Tax
Beginning balance	2,765,290	3,175,572	1,982,650
Other comprehensive income (loss) before reclassifications, net of tax	(4,211,540)	(385,231)	1,167,003
Reclassifications, net of tax	25,578	(25,051)	25,919
Other comprehensive income (loss)	(4,185,962)	(410,282)	1,192,922
Ending balance	(1,420,672)	2,765,290	3,175,572
Deferred Acquisition Costs
Increase (Decrease) in AOCI, Net of Tax
Beginning balance	(3,418)	(4,704)	(5,916)
Other comprehensive income (loss) before reclassifications, net of tax	7,668	1,286	1,212
Reclassifications, net of tax	0	0	0
Other comprehensive income (loss)	7,668	1,286	1,212
Ending balance	4,250	(3,418)	(4,704)
Foreign Exchange
Increase (Decrease) in AOCI, Net of Tax
Beginning balance	19,387	23,302	12,058
Other comprehensive income (loss) before reclassifications, net of tax	(19,923)	(3,915)	11,244
Reclassifications, net of tax	0	0	0
Other comprehensive income (loss)	(19,923)	(3,915)	11,244
Ending balance	(536)	19,387	23,302
Pension Adjustments
Increase (Decrease) in AOCI, Net of Tax
Beginning balance	(103,676)	(164,926)	(143,962)
Other comprehensive income (loss) before reclassifications, net of tax	94,055	44,819	(34,103)
Reclassifications, net of tax	10,865	16,431	13,139
Other comprehensive income (loss)	104,920	61,250	(20,964)
Ending balance	$ 1,244	$ (103,676)	$ (164,926)