Retirement Plans and Other Retiree Benefits (Details 7) $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($)
Pension Plan
Estimated amounts that will be amortized from accumulated other comprehensive income [Abstract]
Net actuarial loss	$ 57
Net transition & prior service cost	0
Other Postretirement Benefit Plan
Estimated amounts that will be amortized from accumulated other comprehensive income [Abstract]
Net actuarial loss	17
Net transition & prior service cost	$ 0