Business and Basis of Presentation (Summary Of Adoption Of New Guidance On Unaudited Interim Consolidated Statement For Financial Position) (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Jan. 01, 2023	Dec. 31, 2022		Sep. 30, 2022	Dec. 31, 2021	Jan. 01, 2021	Dec. 31, 2020
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs	$ 6,923,554		$ 6,930,425	[1]	$ 6,824,407	$ 7,029,307	$ 2,493,082
Reinsurance recoverables	36,860,011		37,096,562	[1]
Deferred sales inducements	359,674		381,504	[1]
Income tax assets	2,319,041		1,694,751	[1]
Market risk benefits assets	2,519,234		1,393,237	[1]	1,306,000
Other assets	2,029,917		1,331,427	[1]
TOTAL ASSETS	199,893,920		193,473,118
Policyholders’ account balances	49,662,070		41,912,536	[1]	40,752,545
Future policy benefits	21,257,134		20,829,033	[1]	20,003,692
Market risk benefit liabilities	4,371,178		5,521,601	[1]	$ 5,945,000
Other liabilities	4,720,229		3,597,373	[1]
Total liabilities	196,077,003		188,436,923
Retained earnings / (accumulated deficit)	(941,204)		(994,154)	[1]
Accumulated other comprehensive income (loss)	(739,599)		(10,065)	[1]
Total equity	3,816,917		5,036,195
TOTAL LIABILITIES AND EQUITY	$ 199,893,920		193,473,118
As Previously Reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs			6,616,097					$ 2,433,936
Reinsurance recoverables			34,561,825
Deferred sales inducements			275,574
Income tax assets			1,873,740
Market risk benefits assets			0
Other assets			1,327,393
TOTAL ASSETS			189,299,841
Policyholders’ account balances			41,748,241
Future policy benefits			23,204,533
Market risk benefit liabilities			0
Other liabilities			3,407,156
Total liabilities			184,936,310
Retained earnings / (accumulated deficit)			(95,583)
Accumulated other comprehensive income (loss)			(1,581,300)
Total equity			4,363,531
TOTAL LIABILITIES AND EQUITY			189,299,841
Change of Effect
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs			314,328				74,702
Reinsurance recoverables			2,534,737
Deferred sales inducements			105,930
Income tax assets			(178,989)
Market risk benefits assets			1,393,237
Other assets			4,034
TOTAL ASSETS			4,173,277
Policyholders’ account balances			164,295
Future policy benefits			(2,375,500)
Market risk benefit liabilities			5,521,601
Other liabilities			190,217
Total liabilities			3,500,613
Retained earnings / (accumulated deficit)			(898,571)
Accumulated other comprehensive income (loss)			1,571,235
Total equity		$ 673,000	672,664				$ (271,000)
TOTAL LIABILITIES AND EQUITY			$ 4,173,277

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