Employee Benefit Plans (Expected Future Benefit Payments To Be Paid) (Details) $ in Millions	Dec. 31, 2018 USD ($)
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months	$ 65
Defined Benefit Plan, Expected Future Benefit Payment, Year Two	72
Defined Benefit Plan, Expected Future Benefit Payment, Year Three	80
Defined Benefit Plan, Expected Future Benefit Payment, Year Four	88
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	96
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter	585
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months	13
Defined Benefit Plan, Expected Future Benefit Payment, Year Two	13
Defined Benefit Plan, Expected Future Benefit Payment, Year Three	12
Defined Benefit Plan, Expected Future Benefit Payment, Year Four	12
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	11
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter	$ 53