Employee Benefit Plans (Schedule of Net Funded Status) (Details) - USD ($) $ in Millions		Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Change In Benefit Obligation [Line Items]
Defined Benefit Plan, Plan Assets, Amount		$ 157	$ 133
Defined Benefit Plan, Benefit Obligation		254	220
Defined Benefit Plan, Funded Status of Plan, Total		(97)	(87)
Qualified Plan [Member]
Defined Benefit Plan Change In Benefit Obligation [Line Items]
Defined Benefit Plan, Plan Assets, Amount		157	133
Defined Benefit Plan, Benefit Obligation		160	139
Defined Benefit Plan, Funded Status of Plan, Total		(3)	(6)
Nonqualified Plan [Member]
Defined Benefit Plan Change In Benefit Obligation [Line Items]
Defined Benefit Plan, Plan Assets, Amount	[1]	0	0
Defined Benefit Plan, Benefit Obligation	[1]	94	81
Defined Benefit Plan, Funded Status of Plan, Total	[1]	$ (94)	$ (81)

[1] For non-qualified plans, there are no required funding levels.