Employee Benefit Plans (Expected Future Benefit Payments To Be Paid) (Details) $ in Millions	Dec. 31, 2019 USD ($)
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months	$ 96
Defined Benefit Plan, Expected Future Benefit Payment, Year Two	83
Defined Benefit Plan, Expected Future Benefit Payment, Year Three	88
Defined Benefit Plan, Expected Future Benefit Payment, Year Four	93
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	101
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter	579
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months	16
Defined Benefit Plan, Expected Future Benefit Payment, Year Two	15
Defined Benefit Plan, Expected Future Benefit Payment, Year Three	14
Defined Benefit Plan, Expected Future Benefit Payment, Year Four	13
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	13
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter	$ 51