Policyholders' Account Balances (Balance of and Changes in Policyholders' Account Balances) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2025	Sep. 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	341,592	$ 323,706
Unearned revenue reserve	4,900,569	4,248,795
Other	109,765	106,109
Total Policyholders' account balance	$ 82,670,415	$ 65,658,560
Weighted-average crediting rate	1.95%	2.28%
Net amount at risk	$ 361,086,098	$ 336,737,805
Cash surrender value	73,294,892	57,287,463
Total
Additional Liability, Long-Duration Insurance [Roll Forward]
Balance, beginning of period	65,105,807	49,142,691
Deposits	11,376,547	11,643,193
Interest credited(4)	1,045,005	942,831
Policy charges	(1,473,541)	(1,395,264)
Surrenders and withdrawals	(2,163,501)	(1,563,648)
Benefit payments	(200,956)	(114,435)
Transfer to (from) Policyholder Account Balance (to) from Separate Account	341,592	323,706
Change in market value and other adjustments	3,629,128	2,324,582
Balance, end of period	77,660,081	61,303,656
Fixed Annuities
Additional Liability, Long-Duration Insurance [Roll Forward]
Balance, beginning of period	11,197,337	6,164,313
Deposits	4,057,964	4,149,820
Interest credited(4)	275,067	150,642
Policy charges	(37,914)	(4,168)
Surrenders and withdrawals	(658,623)	(409,573)
Benefit payments	(85,274)	(42,344)
Transfer to (from) Policyholder Account Balance (to) from Separate Account	0	0
Change in market value and other adjustments	184,070	218,164
Balance, end of period	14,932,627	10,226,854
Total Policyholders' account balance	$ 6,704,720	$ 4,484,236
Weighted-average crediting rate	2.81%	2.45%
Net amount at risk	$ 1	$ 16
Cash surrender value	13,499,825	9,070,551
Variable Annuity
Additional Liability, Long-Duration Insurance [Roll Forward]
Balance, beginning of period	33,217,331	22,810,665
Deposits	5,582,233	5,900,477
Interest credited(4)	513,687	365,807
Policy charges	(54,154)	(21,369)
Surrenders and withdrawals	(788,183)	(558,335)
Benefit payments	(16,527)	(21,840)
Transfer to (from) Policyholder Account Balance (to) from Separate Account	8,997	48,394
Change in market value and other adjustments	2,883,756	1,967,187
Balance, end of period	41,347,140	30,490,986
Total Policyholders' account balance	$ 2,225,815	$ 2,631,165
Weighted-average crediting rate	1.84%	1.83%
Net amount at risk	$ 0	$ 0
Cash surrender value	39,974,409	29,028,016
Variable/Universal Life
Additional Liability, Long-Duration Insurance [Roll Forward]
Balance, beginning of period	20,691,139	20,167,713
Deposits	1,736,350	1,592,896
Interest credited(4)	256,251	426,382
Policy charges	(1,381,473)	(1,369,727)
Surrenders and withdrawals	(716,695)	(595,740)
Benefit payments	(99,155)	(50,251)
Transfer to (from) Policyholder Account Balance (to) from Separate Account	332,595	275,312
Change in market value and other adjustments	561,302	139,231
Balance, end of period	21,380,314	20,585,816
Total Policyholders' account balance	$ 17,486,396	$ 17,479,678
Weighted-average crediting rate	1.62%	2.79%
Net amount at risk	$ 361,086,097	$ 336,737,789
Cash surrender value	$ 19,820,658	$ 19,188,896