Investments (Realized Investment Gains Losses, Net) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	$ 714,709	$ (122,502)	$ 1,498,816	$ (45,894)
Fixed maturities
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	(26,717)	1,369	(63,438)	(1,369)
Commercial mortgage and other loans
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	(5,756)	910	(6,359)	1,148
Other invested assets
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	1,894	887	3,536	909
Derivatives
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	745,236	(125,662)	1,565,289	(46,571)
Short-term investments and cash equivalents
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	$ 52	$ (6)	$ (212)	$ (11)