Employee Benefits Schedule of Expected Benefit Payments (Details) $ in Millions	Dec. 31, 2015 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Benefit Payments in Year One	$ 44
Defined Benefit Plan, Expected Future Benefit Payments in Year Two	45
Defined Benefit Plan, Expected Future Benefit Payments in Year Three	47
Defined Benefit Plan, Expected Future Benefit Payments in Year Four	49
Defined Benefit Plan, Expected Future Benefit Payments in Year Five	49
Defined Benefit Plan, Expected Future Benefit Payments in Five Fiscal Years Thereafter	262
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Benefit Payments in Year One	37
Defined Benefit Plan, Expected Future Benefit Payments in Year Two	38
Defined Benefit Plan, Expected Future Benefit Payments in Year Three	40
Defined Benefit Plan, Expected Future Benefit Payments in Year Four	41
Defined Benefit Plan, Expected Future Benefit Payments in Year Five	42
Defined Benefit Plan, Expected Future Benefit Payments in Five Fiscal Years Thereafter	226
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Benefit Payments in Year One	5
Defined Benefit Plan, Expected Future Benefit Payments in Year Two	5
Defined Benefit Plan, Expected Future Benefit Payments in Year Three	5
Defined Benefit Plan, Expected Future Benefit Payments in Year Four	5
Defined Benefit Plan, Expected Future Benefit Payments in Year Five	5
Defined Benefit Plan, Expected Future Benefit Payments in Five Fiscal Years Thereafter	26
Non Qualified Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Benefit Payments in Year One	2
Defined Benefit Plan, Expected Future Benefit Payments in Year Two	2
Defined Benefit Plan, Expected Future Benefit Payments in Year Three	2
Defined Benefit Plan, Expected Future Benefit Payments in Year Four	3
Defined Benefit Plan, Expected Future Benefit Payments in Year Five	2
Defined Benefit Plan, Expected Future Benefit Payments in Five Fiscal Years Thereafter	$ 10