Reinsurance (Reinsurance amounts included in the Statements of Financial Position) (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022		Jun. 30, 2022	Dec. 31, 2021	Jan. 01, 2021
Effects of Reinsurance [Line Items]
Reinsurance recoverables	$ 37,667,480	$ 37,096,562	[1]
Policy loans	1,432,850	505,367
Deferred policy acquisition costs	(6,784,291)	(6,930,425)	[1]	$ (6,721,014)	$ (7,029,307)	$ (2,493,082)
Deferred sale inducement	(366,916)	(381,504)	[1]
Market risk benefits assets	2,340,230	1,393,237	[1]	1,423,000
Other assets	1,787,731	1,331,427	[1]
Future policy benefits	21,977,994	20,829,033	[1]	21,026,266
Market risk benefit liabilities	5,089,766	5,521,601	[1]	$ 6,686,000
Other liabilities	4,540,528	3,597,373	[1]
Impacts of Reinsurance
Effects of Reinsurance [Line Items]
Reinsurance recoverables	37,667,480	37,096,562
Policy loans	1,054,894	1,011,112
Deferred policy acquisition costs	(3,270,979)	(3,343,270)
Deferred sale inducement	(36,745)	(38,146)
Market risk benefits assets	1,174,612	543,177
Other assets	1,648,435	1,146,794
Policyholders' account balance	6,245,990	7,157,639
Future policy benefits	6,747,348	6,320,863
Market risk benefit liabilities	230,773	120,916
Other liabilities	3,793,074	2,891,433
Unaffiliated activity
Effects of Reinsurance [Line Items]
Deferred policy acquisition costs	(84,646)	(111,379)
Market risk benefits assets	752,567	64,738
Other assets	1,540,310	1,034,000
Policyholders' account balance	1,986,974	2,771,961
Future policy benefits	315	0
Market risk benefit liabilities	118,963	40,731
Other liabilities	$ 1,656,479	$ 820,185

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