Investments (Realized Investment Gains Losses, Net) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Schedule Of Gain Loss On Investments [Line Items]
Realized Investment gains (losses), net	$ 108,643	$ (120,679)
Fixed maturities
Schedule Of Gain Loss On Investments [Line Items]
Realized Investment gains (losses), net	(6,837)	(8,221)
Commercial mortgage and other loans
Schedule Of Gain Loss On Investments [Line Items]
Realized Investment gains (losses), net	(5,781)	(1,278)
Other invested assets
Schedule Of Gain Loss On Investments [Line Items]
Realized Investment gains (losses), net	15,511	5,627
Derivatives
Schedule Of Gain Loss On Investments [Line Items]
Realized Investment gains (losses), net	106,097	(118,270)
Short-term investments and cash equivalents
Schedule Of Gain Loss On Investments [Line Items]
Realized Investment gains (losses), net	$ (347)	$ 1,463