Investments (Realized Investment Gains Losses, Net) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Schedule Of Gain Loss On Investments [Line Items]
Realized Investment gains (losses), net	$ 838,882	$ 7,694	$ 861,882	$ (112,985)
Fixed maturities
Schedule Of Gain Loss On Investments [Line Items]
Realized Investment gains (losses), net	(8,631)	(2)	(15,468)	(8,223)
Commercial mortgage and other loans
Schedule Of Gain Loss On Investments [Line Items]
Realized Investment gains (losses), net	1,162	(806)	(4,619)	(2,084)
Other invested assets
Schedule Of Gain Loss On Investments [Line Items]
Realized Investment gains (losses), net	17,635	7,569	33,146	13,196
Derivatives
Schedule Of Gain Loss On Investments [Line Items]
Realized Investment gains (losses), net	828,449	600	848,903	(117,670)
Short-term investments and cash equivalents
Schedule Of Gain Loss On Investments [Line Items]
Realized Investment gains (losses), net	$ 267	$ 333	$ (80)	$ 1,796