Derivative Instruments (Cumulative Basis Adjustments For Fair Value Hedges) (Details) $ in Millions	Dec. 31, 2019 USD ($)
Fixed Maturity AFS Securities [Member]
Derivatives, Fair Value [Line Items]
Amortized cost of hedged assets	$ 776
Cumulative amount of fair value hedging adjustment included in the amortized cost of the hedged assets	202
Long-term Debt [Member]
Derivatives, Fair Value [Line Items]
Amortized cost of hedged liabilities	(1,035)	[1]
Cumulative amount of fair value hedging adjustment included in the amortized cost of the hedged liabilities	(160)	[1]
Discontinued Hedges [Member] | Long-term Debt [Member]
Derivatives, Fair Value [Line Items]
Cumulative amount of fair value hedging adjustment included in the amortized cost of the hedged liabilities	$ (118)

[1] Includes $(118) million of unamortized adjustments from discontinued hedges as of December 31, 2019.