Derivatives (Fair Value Hedges) (Details) - Designated as Hedging Instrument [Member] - USD ($)	Sep. 30, 2021	Dec. 31, 2020
Fixed maturity securities AFS
Derivative Instruments, Gain (Loss) [Line Items]
Hedged Asset, Discontinued Fair Value Hedge, Cumulative Increase (Decrease)	$ 169	$ (1,000,000)
Debt Instruments, Carrying Amount	2,117,000,000	2,699,000,000
Hedged Asset, Fair Value Hedge, Cumulative Increase (Decrease)	(1,000,000)	(1,000,000)
Mortgages [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Debt Instruments, Carrying Amount	749,000,000	952,000,000
Hedged Asset, Fair Value Hedge, Cumulative Increase (Decrease)	(3,000,000)	20,000,000
Future policy benefits [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Debt Instruments, Carrying Amount	(4,713,000,000)	(5,512,000,000)
Hedged Asset, Fair Value Hedge, Cumulative Increase (Decrease)	$ (911,000,000)	$ (1,307,000,000)