Derivative Instruments (Cumulative Basis Adjustments For Fair Value Hedges) (Details) $ in Millions	Sep. 30, 2019 USD ($)
Fixed Maturity AFS Securities [Member]
Derivatives, Fair Value [Line Items]
Amortized cost of hedged assets	$ 816
Cumulative amount of fair value hedging adjustment included in the amortized cost of the hedged assets	240
Long-term Debt [Member]
Derivatives, Fair Value [Line Items]
Amortized cost of hedged liabilities	(1,087)	[1]
Cumulative amount of fair value hedging adjustment included in the amortized cost of the hedged liabilities	(212)	[1]
Discontinued Hedges [Member]
Derivatives, Fair Value [Line Items]
Cumulative amount of fair value hedging adjustment included in the amortized cost of the hedged assets	$ (119)

[1] The balance includes $(119) million of unamortized adjustments from discontinued hedges as of September 30, 2019.