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, 2020	Sep. 30, 2020
Fair Value Assets And Liabilities Measured On Recurring Basis Level 3 Activity [Line Items]
Unrealized gains (losses) included in OCI, net	$ 143	$ (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	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		(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	3
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	$ 1	$ (4)