Fair Value of Financial Instruments (Changes in Unrealized Gains (Losses) Included in OCI) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Fair Value Assets And Liabilities Measured On Recurring Basis Level 3 Activity [Line Items]
Unrealized gains (losses) included in OCI, net	$ (78)	$ 143	$ (132)	$ (160)
Fixed Maturity AFS Securities [Member] | Corporate Bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Level 3 Activity [Line Items]
Unrealized gains (losses) included in OCI, net	(82)	139	(139)	(154)
Fixed Maturity AFS Securities [Member] | Foreign Government Bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Level 3 Activity [Line Items]
Unrealized gains (losses) included in OCI, net	(3)		(11)	(2)
Fixed Maturity AFS Securities [Member] | ABS [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Level 3 Activity [Line Items]
Unrealized gains (losses) included in OCI, net	(1)	3	(5)
Fixed Maturity AFS Securities [Member] | Hybrid And Redeemable Preferred Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Level 3 Activity [Line Items]
Unrealized gains (losses) included in OCI, net	5	$ 1	18	$ (4)
Fixed Maturity AFS Securities [Member] | Mortgage Loans On Real Estate [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Level 3 Activity [Line Items]
Unrealized gains (losses) included in OCI, net	$ 3		$ 5