Deferred Policy Acquisition Costs, Deferred Reinsurance Losses, Deferred Reinsurance Gains And Deferred Sales Inducements (Balance of and Changes in Deferred Reinsurance Gain) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Reinsurance Recoverable, Allowance for Credit Gain [Roll Forward]
Balance, beginning of period	$ 1,673,290	$ 1,492,856
Amortization	(38,388)	(19,718)
Other	1,069,266
Balance, end of period	2,704,168	1,473,138
Fixed Annuities
Reinsurance Recoverable, Allowance for Credit Gain [Roll Forward]
Balance, beginning of period	48,073	57,898
Amortization	(2,688)	(1,622)
Other	(9)
Balance, end of period	45,376	56,276
Variable Annuities
Reinsurance Recoverable, Allowance for Credit Gain [Roll Forward]
Balance, beginning of period	261,721	0
Amortization	(5,056)	0
Other	(40)
Balance, end of period	256,625	0
Variable/Universal Life
Reinsurance Recoverable, Allowance for Credit Gain [Roll Forward]
Balance, beginning of period	1,363,496	1,434,958
Amortization	(30,644)	(18,096)
Other	1,069,315
Balance, end of period	2,402,167	$ 1,416,862
Variable/Universal Life | Somerset Re
Reinsurance Recoverable, Allowance for Credit Gain [Roll Forward]
Other	1,186,000
Variable/Universal Life | PURC
Reinsurance Recoverable, Allowance for Credit Gain [Roll Forward]
Other	$ 116,000