Investments (Realized Investment Gains Losses, Net) (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022		Jun. 30, 2023	Jun. 30, 2022
Schedule Of Gain Loss On Investments [Line Items]
Realized Investment gains (losses), net	$ 7,694	$ 360,219	[1]	$ (112,985)	$ 713,500	[2]
Fixed maturities
Schedule Of Gain Loss On Investments [Line Items]
Realized Investment gains (losses), net	(2)	(26,717)		(8,223)	(63,438)
Commercial mortgage and other loans
Schedule Of Gain Loss On Investments [Line Items]
Realized Investment gains (losses), net	(806)	(5,756)		(2,084)	(6,359)
Other invested assets
Schedule Of Gain Loss On Investments [Line Items]
Realized Investment gains (losses), net	7,569	1,894		13,196	3,536
Derivatives
Schedule Of Gain Loss On Investments [Line Items]
Realized Investment gains (losses), net	600	390,746		(117,670)	779,973
Short-term investments and cash equivalents
Schedule Of Gain Loss On Investments [Line Items]
Realized Investment gains (losses), net	$ 333	$ 52		$ 1,796	$ (212)

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

[2] Prior period amounts adjusted for the implementation of ASU 2018-12: Targeted Improvements to the Accounting for Long-Duration Contracts.