Deferred Policy Acquisition Costs, Deferred Reinsurance Losses, Deferred Reinsurance Gains And Deferred Sales Inducements (Balance of and Changes in DAC) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023		Sep. 30, 2022
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Deferred Policy Acquisition Cost, Beginning Balance	$ 6,930,425	[1]	$ 7,029,307
Capitalization	785,410		721,235
Amortization expense	(398,884)		(384,384)
Other	(393,397)		(541,751)
Balance, end of period	6,923,554		6,824,407
Fixed Annuities
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Deferred Policy Acquisition Cost, Beginning Balance	102,251		84,479
Capitalization	77,409		14,235
Amortization expense	(15,270)		(10,059)
Other	0		0
Balance, end of period	164,390		88,655
Variable Annuities
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Deferred Policy Acquisition Cost, Beginning Balance	3,736,454		3,806,733
Capitalization	180,239		213,698
Amortization expense	(245,590)		(255,420)
Other	(393,385)		0
Balance, end of period	3,277,718		3,765,011
Term Life
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Deferred Policy Acquisition Cost, Beginning Balance	648,837		577,084
Capitalization	114,860		97,395
Amortization expense	(47,256)		(40,383)
Other	0		(322)
Balance, end of period	716,441		633,774
Variable/Universal Life
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Deferred Policy Acquisition Cost, Beginning Balance	2,442,883		2,561,011
Capitalization	412,902		395,907
Amortization expense	(90,768)		(78,522)
Other	(12)		(541,429)
Balance, end of period	$ 2,765,005		$ 2,336,967

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