Investments (Realized Investment Gains Losses, Net) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023		Mar. 31, 2022
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	$ (120,679)	[1]	$ 353,281	[2]
Fixed maturities
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	(8,221)		(36,721)
Commercial mortgage and other loans
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	(1,278)		(603)
Other invested assets
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	5,627		1,642
Derivatives
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	(118,270)		389,227
Short-term investments and cash equivalents
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	$ 1,463		$ (264)

[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.