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	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Reinsurance Recoverable, Allowance for Credit Gain [Roll Forward]
Balance, beginning of period	$ 1,673,290	$ 1,492,856
Amortization	(110,041)	(71,240)
Other	1,092,415	277,161
Balance, end of period	2,655,664	1,698,777
Fixed Annuities
Reinsurance Recoverable, Allowance for Credit Gain [Roll Forward]
Balance, beginning of period	48,073	57,898
Amortization	(8,109)	(7,141)
Other	118	28
Balance, end of period	40,082	50,785
Variable Annuities
Reinsurance Recoverable, Allowance for Credit Gain [Roll Forward]
Balance, beginning of period	261,721	0
Amortization	(15,237)	(10,265)
Other	98	(277,133)
Balance, end of period	246,582	266,868
Variable/Universal Life
Reinsurance Recoverable, Allowance for Credit Gain [Roll Forward]
Balance, beginning of period	1,363,496	1,434,958
Amortization	(86,695)	(53,834)
Other	1,092,199	0
Balance, end of period	2,369,000	$ 1,381,124
Variable/Universal Life | Somerset Re
Reinsurance Recoverable, Allowance for Credit Gain [Roll Forward]
Other	1,207,000
Variable/Universal Life | PURC
Reinsurance Recoverable, Allowance for Credit Gain [Roll Forward]
Other	$ 116,000