Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Statement of Comprehensive Income [Abstract]
Net income	$ 1,070,762	$ 970,755	$ 894,386
Unrealized gains (losses) on fixed maturities:
Unrealized holding gains (losses) arising during period	(630,042)	671,211	(5,332,818)
Other reclassification adjustments included in net income	3,764	80,238	32,377
Foreign exchange adjustment on fixed maturities recorded at fair value	3,469	(715)	1,749
Total unrealized investment gains (losses)	(622,809)	750,734	(5,298,692)
Less applicable tax (expense) benefit	130,787	(157,658)	1,112,730
Unrealized gains (losses) on investments, net of tax	(492,022)	593,076	(4,185,962)
Future Policy Benefits:
Change in discount rate on future policy benefits	1,567,530	(731,883)	7,021,147
Less applicable tax (expense) benefit	(329,181)	153,696	(1,474,441)
Future policy benefit adjustments, net of tax	1,238,349	(578,187)	5,546,706
Foreign exchange translation:
Foreign exchange translation adjustments, other than securities	(33,516)	8,102	(26,494)
Less applicable tax (expense) benefit	7,040	(1,702)	5,565
Foreign exchange translation adjustments, other than securities, net of tax	(26,476)	6,400	(20,929)
Pension:
Amortization of pension costs	474	(390)	13,754
Plan amendments	(1,212)	0	0
Experience gain (loss)	29,659	(3,907)	119,055
Pension adjustments	28,921	(4,297)	132,809
Less applicable tax (expense) benefit	(6,073)	902	(27,889)
Pension adjustments, net of tax	22,848	(3,395)	104,920
Other comprehensive income (loss)	742,699	17,894	1,444,735
Comprehensive income (loss)	$ 1,813,461	$ 988,649	$ 2,339,121