Employee Benefit Plans (Expected Future Benefit Payments To Be Paid) (Details) $ in Millions	Dec. 31, 2020 USD ($)
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months	$ 84
Defined Benefit Plan, Expected Future Benefit Payment, Year Two	90
Defined Benefit Plan, Expected Future Benefit Payment, Year Three	96
Defined Benefit Plan, Expected Future Benefit Payment, Year Four	101
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	108
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter	620
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	14
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	13
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter	$ 50