Liability For Future Policy Benefits (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022		Sep. 30, 2023	Sep. 30, 2022		Dec. 31, 2022	Dec. 31, 2021
Liability for Future Policy Benefit, Expected Future Policy Benefit [Roll Forward]
Other adjustments	$ (6,565)	$ 2,935	[1]	$ (1,030)	$ (42,865)	[1]
Balance after transition	17,216,882	17,684,170		17,216,882	17,684,170
Balance, end of period, pre-flooring	6,937,260			6,937,260
Flooring impact, end of period	1,773			1,773
Balance, end of period, post flooring	20,152,378	18,967,414		20,152,378	18,967,414
Interest accrual				360,309	318,069
Other Businesses
Liability for Future Policy Benefit, Expected Future Policy Benefit [Roll Forward]
Balance after transition	1,838	2,186		1,838	2,186
Nonparticipating Traditional And Limited-Pay Business
Liability for Future Policy Benefit, Expected Future Policy Benefit [Roll Forward]
Gain in net income				(35,000)	97,000
Loss in net income				34,000	99,000
Term Life
Liability for Future Policy Benefit, Expected Net Premium [Roll Forward]
Balance, beginning of period				10,911,794	12,485,056
Effect of cumulative changes in discount rate assumptions, beginning of period				554,896	(1,826,120)
Balance at original discount rate, beginning of period				11,466,690	10,658,936
Effect of assumption update							$ (790)	$ 1,295,294
Effect of actual variances from expected experience and other activity							(144,504)	(86,611)
Adjusted balance, beginning of period				11,321,396	11,867,619
Issuances				512,379	317,058
Net premiums / considerations collected				(1,008,159)	(1,000,325)
Interest accrual				391,662	392,917
Balance at original discount rate, end of period	11,217,278	11,577,269		11,217,278	11,577,269
Effect of cumulative changes in discount rate assumptions, end of period	(939,494)	(751,597)		(939,494)	(751,597)
Balance, end of period	10,277,784	10,825,672		10,277,784	10,825,672
Liability for Future Policy Benefit, Expected Future Policy Benefit [Roll Forward]
Balance prior to transition				17,835,251	20,937,097
Effect of cumulative changes in discount rate assumptions, beginning of period				962,034	(3,607,275)
Balance prior to transition				18,797,285	17,329,822
Effect of assumption update							(1,044)	1,756,995
Effect of actual variances from expected experience and other activity							(191,864)	(171,967)
Adjusted balance, beginning of period				18,604,377	18,914,850
Issuances				512,379	317,058
Interest accrual				670,905	664,008
Benefit payments				(1,019,151)	(1,046,082)
Other adjustments				2,845	3,692
Balance after transition, at original discount rate	18,771,355	18,853,526		18,771,355	18,853,526
Effect of cumulative changes in discount rate assumptions, end of period	(1,767,981)	(1,370,645)		(1,767,981)	(1,370,645)
Balance after transition	17,003,374	17,482,881		17,003,374	17,482,881
Balance, end of period, pre-flooring	6,725,590			6,725,590
Flooring impact, end of period	1,773			1,773
Balance, end of period, post flooring	6,727,363	6,657,281		6,727,363	6,657,281
Reinsurance recoverable	6,241,505	6,293,473		6,241,505	6,293,473
Balance after reinsurance recoverable, end of period, post-flooring	485,858	363,808		485,858	363,808
Term Life | Gross Basis
Liability for Future Policy Benefit, Expected Future Policy Benefit [Roll Forward]
Undiscounted expected future gross premiums	21,914,391	22,344,548		21,914,391	22,344,548
Discounted expected future gross premiums (at original discount rate)	15,083,578	15,403,622		15,083,578	15,403,622
Discounted expected future gross premiums (at current discount rate)	13,840,343	14,404,899		13,840,343	14,404,899
Undiscounted expected future benefits and expenses	$ 29,147,479	$ 29,477,887		29,147,479	29,477,887
Interest accrual				279,242	271,091
Gross Premiums				$ 1,351,460	$ 1,379,044
Weighted-average duration of the liability in years (at original discount rate)	10 years	11 years		10 years	11 years
Weighted-average duration of the liability in years (at current discount rate)	9 years	10 years		9 years	10 years
Weighted-average interest rate (at original discount rate)	5.18%	5.26%		5.18%	5.26%
Weighted-average interest rate (at current discount rate)	6.02%	5.67%		6.02%	5.67%
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							(1,257)	(1,032)
Issuances				28,889	23,787
Net premiums / considerations collected				(27,632)	(22,755)
Interest accrual				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 prior to transition				204,727	237,065
Effect of cumulative changes in discount rate assumptions, beginning of period				24,876	(16,704)
Balance prior to transition				229,603	220,361
Effect of assumption update							0	0
Effect of actual variances from expected experience and other activity							6,793	(1,489)
Adjusted balance, beginning of period				236,396	218,872
Issuances				28,889	23,787
Interest accrual				6,300	5,798
Benefit payments				(25,504)	(20,263)
Other adjustments				(84)	(285)
Balance after transition, at original discount rate	245,997	227,909		245,997	227,909
Effect of cumulative changes in discount rate assumptions, end of period	(34,327)	(28,806)		(34,327)	(28,806)
Balance after transition	211,670	199,103		211,670	199,103
Balance, end of period, pre-flooring	211,670			211,670
Flooring impact, end of period	0			0
Balance, end of period, post flooring	211,670	199,103		211,670	199,103
Reinsurance recoverable	17,097	16,408		17,097	16,408
Balance after reinsurance recoverable, end of period, post-flooring	194,573	182,695		194,573	182,695
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	$ 328,212	$ 303,385		328,212	303,385
Interest accrual				6,300	5,798
Gross Premiums				$ 32,677	$ 25,058
Weighted-average duration of the liability in years (at original discount rate)	7 years	7 years		7 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)	3.62%	3.55%		3.62%	3.55%
Weighted-average interest rate (at current discount rate)	5.95%	5.58%		5.95%	5.58%
Fixed Annuity Netting
Liability for Future Policy Benefit, Expected Net Premium [Roll Forward]
Adjusted balance, beginning of period				$ (1,257)	$ (1,032)
Term Life And Fixed Annuities
Liability for Future Policy Benefit, Expected Net Premium [Roll Forward]
Balance, beginning of period				10,911,794	12,485,056
Effect of cumulative changes in discount rate assumptions, beginning of period				554,896	(1,826,120)
Balance at original discount rate, beginning of period				11,466,690	10,658,936
Effect of assumption update							(790)	1,295,294
Effect of actual variances from expected experience and other activity							(145,761)	(87,643)
Adjusted balance, beginning of period				11,320,139	11,866,587
Issuances				541,268	340,845
Net premiums / considerations collected				(1,035,791)	(1,023,080)
Interest accrual				391,662	392,917
Balance at original discount rate, end of period	$ 11,217,278	$ 11,577,269		11,217,278	11,577,269
Effect of cumulative changes in discount rate assumptions, end of period	(939,494)	(751,597)		(939,494)	(751,597)
Balance, end of period	10,277,784	10,825,672		10,277,784	10,825,672
Liability for Future Policy Benefit, Expected Future Policy Benefit [Roll Forward]
Balance, end of period, post flooring	6,939,033	6,856,384		6,939,033	6,856,384
Reinsurance recoverable	6,258,602	6,309,881		6,258,602	6,309,881
Balance after reinsurance recoverable, end of period, post-flooring	680,431	546,503		680,431	546,503
Term Life And Fixed Annuities | Total
Liability for Future Policy Benefit, Expected Future Policy Benefit [Roll Forward]
Balance prior to transition				18,039,978	21,174,162
Effect of cumulative changes in discount rate assumptions, beginning of period				986,910	(3,623,979)
Balance prior to transition				19,026,888	17,550,183
Effect of assumption update							(1,044)	1,756,995
Effect of actual variances from expected experience and other activity							$ (185,071)	$ (173,456)
Adjusted balance, beginning of period				18,840,773	19,133,722
Issuances				541,268	340,845
Interest accrual				677,205	669,806
Benefit payments				(1,044,655)	(1,066,345)
Other adjustments				2,761	3,407
Balance after transition, at original discount rate	19,017,352	19,081,435		19,017,352	19,081,435
Effect of cumulative changes in discount rate assumptions, end of period	(1,802,308)	(1,399,451)		(1,802,308)	(1,399,451)
Balance after transition	$ 17,215,044	$ 17,681,984		$ 17,215,044	$ 17,681,984

[1] Prior period amounts adjusted for the implementation of ASU 2018-12: Targeted Improvements to the Accounting for Long-Duration Contracts.