Business and Basis of Presentation (Transition Adjustment Roll Forward Of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands			9 Months Ended
		Jan. 01, 2021	Sep. 30, 2023	Sep. 30, 2022
Accumulated Other Comprehensive Income Transition Adjustment [Roll Forward]
Beginning Balance	[1]		$ (10,065)
Ending Balance			(739,599)
Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income Transition Adjustment [Roll Forward]
Beginning Balance			(10,065)	$ 396,454
Ending Balance		$ 880,548	(739,599)	$ 10,997
As Previously Reported
Accumulated Other Comprehensive Income Transition Adjustment [Roll Forward]
Beginning Balance			(1,581,300)
As Previously Reported | Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income Transition Adjustment [Roll Forward]
Beginning Balance		546,128
Change of Effect
Accumulated Other Comprehensive Income Transition Adjustment [Roll Forward]
Beginning Balance			$ 1,571,235
Change of Effect | Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income Transition Adjustment [Roll Forward]
Interest rate remeasurement of future policy benefits		(196,526)
Reclassification of market risk benefits non-performance risk to accumulated other comprehensive income		722,837
Unwinding amounts related to unrealized investment gains and losses		(102,042)
Change in operating joint ventures		(753)
Total pre-tax adjustments		423,516
Tax impacts		$ (89,096)

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