Liability For Future Policy Benefits (Benefit Reserves) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024	Dec. 31, 2023
Liability for Future Policy Benefit, Expected Future Policy Benefit [Roll Forward]
Other adjustments	$ (6,582)	$ 12,005
Balance, end of period	18,137,748	18,227,141
Other Businesses
Liability for Future Policy Benefit, Expected Future Policy Benefit [Roll Forward]
Balance, end of period	1,410	1,675
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 actual variances from expected experience and other activity			$ (56,837)	$ (54,196)
Adjusted balance, beginning of period	10,925,308	11,099,348
Issuances	194,679	192,492
Net premiums / considerations collected	(325,511)	(329,743)
Interest accrual	128,423	129,053
Other adjustments	9	(78)
Balance at original discount rate, end of period	10,922,908	11,091,072
Effect of cumulative changes in discount rate assumptions, end of period	(453,082)	(434,791)
Balance, end of period	10,469,826	10,656,281
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 actual variances from expected experience and other activity			(65,080)	(65,431)
Adjusted balance, beginning of period	18,715,992	18,692,347
Issuances	194,678	192,492
Interest accrual	225,260	223,989
Benefit payments	(362,895)	(368,247)
Other adjustments	1,937	(23)
Balance at original discount rate, end of period	18,774,972	18,740,558
Effect of cumulative changes in discount rate assumptions, end of period	(887,904)	(742,789)
Balance, end of period	17,887,068	17,997,769
Balance, end of period, pre-flooring	7,417,242	7,341,488
Flooring impact, end of period	44	44
Balance, end of period, post flooring	7,417,286	7,341,532
Reinsurance recoverable	6,832,580	6,650,332
Balance after reinsurance recoverables, end of period, post-flooring	584,706	691,200
Term Life | Gross Basis
Liability for Future Policy Benefit, Expected Future Policy Benefit [Roll Forward]
Undiscounted expected future gross premiums	21,792,468	21,812,112
Discounted expected future gross premiums (at original discount rate)	14,843,715	14,968,218
Discounted expected future gross premiums (at current discount rate)	14,266,715	14,408,614
Undiscounted expected future benefits and expenses	$ 29,143,806	$ 29,069,972
Weighted-average duration of the liability in years (at original discount rate)	10 years	10 years
Weighted-average duration of the liability in years (at current discount rate)	9 years	10 years
Weighted-average interest rate (at original discount rate)	5.12%	5.16%
Weighted-average interest rate (at current discount rate)	5.44%	5.29%
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 actual variances from expected experience and other activity			0	(290)
Issuances	11,076	8,595
Net premiums / considerations collected	(11,076)	(8,305)
Interest accrual	0	0
Other adjustments	0	0
Balance at original discount rate, end of period	0	0
Effect of cumulative changes in discount rate assumptions, end of period	0	0
Balance, end of period	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 actual variances from expected experience and other activity			1,139	(369)
Adjusted balance, beginning of period	258,667	247,940
Issuances	11,076	8,595
Interest accrual	2,492	2,204
Benefit payments	(8,633)	(7,544)
Other adjustments	0	(34)
Balance at original discount rate, end of period	263,602	251,161
Effect of cumulative changes in discount rate assumptions, end of period	(14,332)	(23,464)
Balance, end of period	249,270	227,697
Balance, end of period, pre-flooring	249,270	227,697
Flooring impact, end of period	0	0
Balance, end of period, post flooring	249,270	227,697
Reinsurance recoverable	20,954	18,428
Balance after reinsurance recoverables, end of period, post-flooring	228,316	209,269
Fixed Annuities | Gross Basis
Liability for Future Policy Benefit, Expected Future Policy Benefit [Roll Forward]
Undiscounted expected future gross premiums	0	0
Discounted expected future gross premiums (at original discount rate)	0	0
Discounted expected future gross premiums (at current discount rate)	0	0
Undiscounted expected future benefits and expenses	$ 357,084	$ 336,830
Weighted-average duration of the liability in years (at original discount rate)	7 years	7 years
Weighted-average duration of the liability in years (at current discount rate)	6 years	6 years
Weighted-average interest rate (at original discount rate)	4.00%	3.76%
Weighted-average interest rate (at current discount rate)	5.33%	5.26%
Fixed Annuity Netting
Liability for Future Policy Benefit, Expected Net Premium [Roll Forward]
Adjusted balance, beginning of period	$ 0	$ (290)
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 actual variances from expected experience and other activity			(56,837)	(54,486)
Adjusted balance, beginning of period	10,925,308	11,099,058
Issuances	205,755	201,087
Net premiums / considerations collected	(336,587)	(338,048)
Interest accrual	128,423	129,053
Other adjustments	9	(78)
Balance at original discount rate, end of period	10,922,908	11,091,072
Effect of cumulative changes in discount rate assumptions, end of period	(453,082)	(434,791)
Balance, end of period	10,469,826	10,656,281
Liability for Future Policy Benefit, Expected Future Policy Benefit [Roll Forward]
Balance, end of period, pre-flooring	7,666,512	7,569,185
Flooring impact, end of period	44	44
Balance, end of period, post flooring	7,666,556	7,569,229
Reinsurance recoverable	6,853,534	6,668,760
Balance after reinsurance recoverables, end of period, post-flooring	813,022	900,469
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 actual variances from expected experience and other activity			$ (63,941)	$ (65,800)
Adjusted balance, beginning of period	18,974,659	18,940,287
Issuances	205,754	201,087
Interest accrual	227,752	226,193
Benefit payments	(371,528)	(375,791)
Other adjustments	1,937	(57)
Balance at original discount rate, end of period	19,038,574	18,991,719
Effect of cumulative changes in discount rate assumptions, end of period	(902,236)	(766,253)
Balance, end of period	$ 18,136,338	$ 18,225,466