Pension, Other Postretirement Benefits and Savings Plans - Amounts Recognized in Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Prior service (credit) cost	$ (4)	$ (4)
Net actuarial loss	2,615	2,643
Gross amount recognized	2,611	2,639
Deferred income taxes	(118)	(128)
Net amount recognized	2,493	2,511
Non-U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Prior service (credit) cost	1	2
Net actuarial loss	685	693
Gross amount recognized	686	695
Deferred income taxes	(115)	(96)
Net amount recognized	571	599
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Prior service (credit) cost	(59)	(104)
Net actuarial loss	68	74
Gross amount recognized	9	(30)
Deferred income taxes	(20)	(9)
Net amount recognized	$ (11)	$ (39)