Liability For Future Policy Benefits (Benefit Reserves) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024	Dec. 31, 2023
Liability for Future Policy Benefit, Expected Future Policy Benefit [Roll Forward]
Other adjustments	$ (13,680)	$ (2,434)	$ 87,208	$ 15,745
Balance, end of period	18,361,044	18,840,135	18,361,044	18,840,135
Other Businesses
Liability for Future Policy Benefit, Expected Future Policy Benefit [Roll Forward]
Balance, end of period	1,474	1,610	1,474	1,610
Nonparticipating Traditional And Limited-Pay Business
Liability for Future Policy Benefit, Expected Future Policy Benefit [Roll Forward]
Gain in net income				(29,000)
Loss in net income				28,000
Term Life
Liability for Future Policy Benefit, Expected Net Premium [Roll Forward]
Balance, beginning of period			10,414,702	10,927,833
Effect of cumulative changes in discount rate assumptions, beginning of period			567,443	225,711
Balance at original discount rate, beginning of period			10,982,145	11,153,544
Effect of assumption update					$ (207,935)	$ 21,466
Effect of actual variances from expected experience and other activity					(82,734)	(198,894)
Adjusted balance, beginning of period			10,691,476	10,976,116
Issuances			600,543	608,144
Net premiums / considerations collected			(999,857)	(992,948)
Interest accrual			384,453	383,336
Other adjustments			41,149	7,091
Balance at original discount rate, end of period	10,717,764	10,981,739	10,717,764	10,981,739
Effect of cumulative changes in discount rate assumptions, end of period	(242,687)	(111,296)	(242,687)	(111,296)
Balance, end of period	10,475,077	10,870,443	10,475,077	10,870,443
Liability for Future Policy Benefit, Expected Future Policy Benefit [Roll Forward]
Balance, beginning of period			17,689,399	18,426,207
Effect of cumulative changes in discount rate assumptions, beginning of period			1,091,673	331,571
Balance at original discount rate, beginning of period			18,781,072	18,757,778
Effect of assumption update					(332,969)	21,480
Effect of actual variances from expected experience and other activity					(84,768)	(245,193)
Adjusted balance, beginning of period			18,363,335	18,534,065
Issuances			600,543	608,144
Interest accrual			672,719	668,751
Benefit payments			(1,092,614)	(1,062,328)
Other adjustments			40,027	10,421
Balance at original discount rate, end of period	18,584,010	18,759,053	18,584,010	18,759,053
Effect of cumulative changes in discount rate assumptions, end of period	(496,333)	(159,410)	(496,333)	(159,410)
Balance, end of period	18,087,677	18,599,643	18,087,677	18,599,643
Balance, end of period, pre-flooring	7,612,600	7,729,200	7,612,600	7,729,200
Flooring impact, end of period	44	44	44	44
Balance, end of period, post flooring	7,612,644	7,729,244	7,612,644	7,729,244
Reinsurance recoverable	6,883,224	6,910,121	6,883,224	6,910,121
Balance after reinsurance recoverables, end of period, post-flooring	729,420	819,123	729,420	819,123
Term Life | Gross Basis
Liability for Future Policy Benefit, Expected Future Policy Benefit [Roll Forward]
Undiscounted expected future gross premiums	22,011,057	21,790,252	22,011,057	21,790,252
Discounted expected future gross premiums (at original discount rate)	14,901,235	14,899,016	14,901,235	14,899,016
Discounted expected future gross premiums (at current discount rate)	14,612,031	14,780,675	14,612,031	14,780,675
Undiscounted expected future benefits and expenses	$ 28,900,904	$ 29,134,537	$ 28,900,904	$ 29,134,537
Weighted-average duration of the liability in years (at original discount rate)	9 years	10 years	9 years	10 years
Weighted-average duration of the liability in years (at current discount rate)	9 years	9 years	9 years	9 years
Weighted-average interest rate (at original discount rate)	5.11%	5.13%	5.11%	5.13%
Weighted-average interest rate (at current discount rate)	5.19%	4.91%	5.19%	4.91%
Fixed Annuities
Liability for Future Policy Benefit, Expected Net Premium [Roll Forward]
Balance, beginning of period			$ 0	$ 0
Effect of cumulative changes in discount rate assumptions, beginning of period			0	0
Balance at original discount rate, beginning of period			0	0
Effect of assumption update					0	0
Effect of actual variances from expected experience and other activity					(103)	201
Issuances			33,584	25,850
Net premiums / considerations collected			(33,481)	(26,051)
Interest accrual			0	0
Other adjustments			0	0
Balance at original discount rate, end of period	$ 0	$ 0	0	0
Effect of cumulative changes in discount rate assumptions, end of period	0	0	0	0
Balance, end of period	0	0	0	0
Liability for Future Policy Benefit, Expected Future Policy Benefit [Roll Forward]
Balance, beginning of period			238,086	228,788
Effect of cumulative changes in discount rate assumptions, beginning of period			19,442	19,521
Balance at original discount rate, beginning of period			257,528	248,309
Effect of assumption update					0	(3,643)
Effect of actual variances from expected experience and other activity					3,276	391
Adjusted balance, beginning of period			260,804	245,057
Issuances			37,384	25,850
Interest accrual			7,829	6,752
Benefit payments			(25,922)	(23,877)
Other adjustments			(171)	(149)
Balance at original discount rate, end of period	279,924	253,633	279,924	253,633
Effect of cumulative changes in discount rate assumptions, end of period	(8,031)	(14,751)	(8,031)	(14,751)
Balance, end of period	271,893	238,882	271,893	238,882
Balance, end of period, pre-flooring	271,893	238,882	271,893	238,882
Flooring impact, end of period	0	0	0	0
Balance, end of period, post flooring	271,893	238,882	271,893	238,882
Reinsurance recoverable	21,717	20,461	21,717	20,461
Balance after reinsurance recoverables, end of period, post-flooring	250,176	218,421	250,176	218,421
Fixed Annuities | Gross Basis
Liability for Future Policy Benefit, Expected Future Policy Benefit [Roll Forward]
Undiscounted expected future gross premiums	0	0	0	0
Discounted expected future gross premiums (at original discount rate)	0	0	0	0
Discounted expected future gross premiums (at current discount rate)	0	0	0	0
Undiscounted expected future benefits and expenses	$ 375,454	$ 341,000	$ 375,454	$ 341,000
Weighted-average duration of the liability in years (at original discount rate)	6 years	7 years	6 years	7 years
Weighted-average duration of the liability in years (at current discount rate)	6 years	6 years	6 years	6 years
Weighted-average interest rate (at original discount rate)	4.15%	3.90%	4.15%	3.90%
Weighted-average interest rate (at current discount rate)	5.07%	4.82%	5.07%	4.82%
Fixed Annuity Netting
Liability for Future Policy Benefit, Expected Net Premium [Roll Forward]
Adjusted balance, beginning of period			$ (103)	$ 201
Term Life And Fixed Annuities
Liability for Future Policy Benefit, Expected Net Premium [Roll Forward]
Balance, beginning of period			10,414,702	10,927,833
Effect of cumulative changes in discount rate assumptions, beginning of period			567,443	225,711
Balance at original discount rate, beginning of period			10,982,145	11,153,544
Effect of assumption update					(207,935)	21,466
Effect of actual variances from expected experience and other activity					(82,837)	(198,693)
Adjusted balance, beginning of period			10,691,373	10,976,317
Issuances			634,127	633,994
Net premiums / considerations collected			(1,033,338)	(1,018,999)
Interest accrual			384,453	383,336
Other adjustments			41,149	7,091
Balance at original discount rate, end of period	$ 10,717,764	$ 10,981,739	10,717,764	10,981,739
Effect of cumulative changes in discount rate assumptions, end of period	(242,687)	(111,296)	(242,687)	(111,296)
Balance, end of period	10,475,077	10,870,443	10,475,077	10,870,443
Liability for Future Policy Benefit, Expected Future Policy Benefit [Roll Forward]
Balance, end of period, pre-flooring	7,884,493	7,968,082	7,884,493	7,968,082
Flooring impact, end of period	44	44	44	44
Balance, end of period, post flooring	7,884,537	7,968,126	7,884,537	7,968,126
Reinsurance recoverable	6,904,941	6,930,582	6,904,941	6,930,582
Balance after reinsurance recoverables, end of period, post-flooring	979,596	1,037,544	979,596	1,037,544
Term Life And Fixed Annuities | Total
Liability for Future Policy Benefit, Expected Future Policy Benefit [Roll Forward]
Balance, beginning of period			17,927,485	18,654,995
Effect of cumulative changes in discount rate assumptions, beginning of period			1,111,115	351,092
Balance at original discount rate, beginning of period			19,038,600	19,006,087
Effect of assumption update					(332,969)	17,837
Effect of actual variances from expected experience and other activity					$ (81,492)	$ (244,802)
Adjusted balance, beginning of period			18,624,139	18,779,122
Issuances			637,927	633,994
Interest accrual			680,548	675,503
Benefit payments			(1,118,536)	(1,086,205)
Other adjustments			39,856	10,272
Balance at original discount rate, end of period	18,863,934	19,012,686	18,863,934	19,012,686
Effect of cumulative changes in discount rate assumptions, end of period	(504,364)	(174,161)	(504,364)	(174,161)
Balance, end of period	$ 18,359,570	$ 18,838,525	$ 18,359,570	$ 18,838,525