Investments (Realized Investment Gains Losses, Net) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Schedule of Gain (Loss) on Investments [Line Items]
Realized investment gains (losses), net	$ 7,488,807	$ (5,260,940)	$ (2,681,320)
Fixed maturities
Schedule of Gain (Loss) on Investments [Line Items]
Realized investment gains (losses), net	1,301,748	(3,802)	(3,931)
Commercial mortgage and other loans
Schedule of Gain (Loss) on Investments [Line Items]
Realized investment gains (losses), net	52,527	(2,242)	(753)
Derivatives
Schedule of Gain (Loss) on Investments [Line Items]
Realized investment gains (losses), net	6,124,265	(5,261,943)	(2,677,559)
Other invested assets
Schedule of Gain (Loss) on Investments [Line Items]
Realized investment gains (losses), net	10,199	4,619	164
Short-term investments and cash equivalents
Schedule of Gain (Loss) on Investments [Line Items]
Realized investment gains (losses), net	$ 68	$ 2,428	$ 759