Employee Benefit Plans (Expected Future Benefit Payments To Be Paid) (Details) $ in Millions	Dec. 31, 2015 USD ($)
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Benefit Payments, Next Twelve Months	$ 93
Defined Benefit Plan, Expected Future Benefit Payments, Year Two	96
Defined Benefit Plan, Expected Future Benefit Payments, Year Three	103
Defined Benefit Plan, Expected Future Benefit Payments, Year Four	110
Defined Benefit Plan, Expected Future Benefit Payments, Year Five	116
Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Years Thereafter	691
Other Postretirement Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Benefit Payments, Next Twelve Months	13
Defined Benefit Plan, Expected Future Benefit Payments, Year Two	12
Defined Benefit Plan, Expected Future Benefit Payments, Year Three	13
Defined Benefit Plan, Expected Future Benefit Payments, Year Four	13
Defined Benefit Plan, Expected Future Benefit Payments, Year Five	13
Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Years Thereafter	$ 68