Schedule of Expected Cash Flow for Pension and Post Retirement Benefit Plans (Details) $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($)
Pension Plan Asset
Defined Benefit Plan Disclosure [Line Items]
Expected employer contributions, 2017	$ 10
Postretirement Benefit Plan Assets
Defined Benefit Plan Disclosure [Line Items]
Expected employer contributions, 2017	1
To Plan Trusts | Pension Plan Asset
Defined Benefit Plan Disclosure [Line Items]
Expected employer contributions, 2017	40
To Plan Trusts | Postretirement Benefit Plan Assets
Defined Benefit Plan Disclosure [Line Items]
Expected employer contributions, 2017	6
To Plan Participants | Pension Plan Asset
Defined Benefit Plan Disclosure [Line Items]
Expected employer contributions, 2017	$ 2