Fair Value of Financial Instruments (Changes in Unrealized Gains (Losses) Included in OCI) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Fair Value Assets And Liabilities Measured On Recurring Basis Level 3 Activity [Line Items]
Unrealized gains (losses) included in OCI, net	$ 79	$ 457	$ (54)	$ 136
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	65	440	(57)	129
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		1	(8)	(1)
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	3	8	(4)	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	$ 11	$ 8	12	$ 3
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