Policyholders' Account Balances (Balance of and Changes in Policyholders' Account Balances) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024
Additional Liability, Long-Duration Insurance [Roll Forward]
Balance, beginning of period	$ 69,628,318
Transfer to (from) Policyholder Account Balance (to) from Separate Account	230,016	$ 210,769
Unearned revenue reserve	4,740,567	4,082,015
Other	108,469	104,172
Total Policyholders' account balance	$ 77,316,563	$ 61,036,866
Weighted-average crediting rate	1.77%	2.31%
Net amount at risk	$ 355,254,270	$ 332,247,819
Cash surrender value	68,042,724	52,757,970
Total
Additional Liability, Long-Duration Insurance [Roll Forward]
Balance, beginning of period	65,105,807	49,142,691
Deposits	7,537,466	7,603,117
Interest credited(4)	607,565	610,970
Policy charges	(976,894)	(922,285)
Surrenders and withdrawals	(1,360,202)	(998,472)
Benefit payments	(137,433)	(71,548)
Transfer to (from) Policyholder Account Balance (to) from Separate Account	230,016	210,769
Change in market value and other adjustments	1,461,202	1,275,437
Balance, end of period	72,467,527	56,850,679
Fixed Annuities
Additional Liability, Long-Duration Insurance [Roll Forward]
Balance, beginning of period	11,197,337	6,164,313
Deposits	2,514,434	2,787,898
Interest credited(4)	169,848	90,612
Policy charges	(24,429)	(87)
Surrenders and withdrawals	(377,791)	(251,521)
Benefit payments	(57,822)	(24,948)
Transfer to (from) Policyholder Account Balance (to) from Separate Account	0	0
Change in market value and other adjustments	60,051	124,805
Balance, end of period	13,481,628	8,891,072
Total Policyholders' account balance	$ 6,063,916	$ 3,701,038
Weighted-average crediting rate	2.75%	2.41%
Net amount at risk	$ 2	$ 20
Cash surrender value	12,125,340	7,711,710
Variable Annuity
Additional Liability, Long-Duration Insurance [Roll Forward]
Balance, beginning of period	33,217,331	22,810,665
Deposits	3,867,628	3,752,999
Interest credited(4)	335,882	240,976
Policy charges	(34,048)	(12,007)
Surrenders and withdrawals	(497,665)	(370,351)
Benefit payments	(10,231)	(12,688)
Transfer to (from) Policyholder Account Balance (to) from Separate Account	28,288	41,403
Change in market value and other adjustments	919,561	1,085,201
Balance, end of period	37,826,746	27,536,198
Total Policyholders' account balance	$ 2,341,994	$ 2,719,828
Weighted-average crediting rate	1.89%	1.91%
Net amount at risk	$ 0	$ 0
Cash surrender value	36,315,560	25,912,600
Variable/Universal Life
Additional Liability, Long-Duration Insurance [Roll Forward]
Balance, beginning of period	20,691,139	20,167,713
Deposits	1,155,404	1,062,220
Interest credited(4)	101,835	279,382
Policy charges	(918,417)	(910,191)
Surrenders and withdrawals	(484,746)	(376,600)
Benefit payments	(69,380)	(33,912)
Transfer to (from) Policyholder Account Balance (to) from Separate Account	201,728	169,366
Change in market value and other adjustments	481,590	65,431
Balance, end of period	21,159,153	20,423,409
Total Policyholders' account balance	$ 17,489,943	$ 17,484,330
Weighted-average crediting rate	0.97%	2.75%
Net amount at risk	$ 355,254,268	$ 332,247,799
Cash surrender value	$ 19,601,824	$ 19,133,660