Pension, Other Postretirement Benefits and Savings Plans - Funded Status Recognized in the Balance Sheet (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Current liabilities	$ (4,957)	$ (4,730)
U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Noncurrent assets	0	9
Current liabilities	(12)	(10)
Noncurrent liabilities	(315)	(256)
Net amount recognized	(327)	(257)
Non-U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Noncurrent assets	249	274
Current liabilities	(19)	(24)
Noncurrent liabilities	(545)	(707)
Net amount recognized	(315)	(457)
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Noncurrent assets	0	0
Current liabilities	(23)	(28)
Noncurrent liabilities	(265)	(328)
Net amount recognized	$ (288)	$ (356)