Pension, Other Postretirement Benefits and Savings Plans - Funded Status Recognized in the Balance Sheet (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Noncurrent liabilities	$ (1,345)	$ (1,515)
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Noncurrent assets	0	0
Current liabilities	(17)	(20)
Noncurrent liabilities	(214)	(262)
Net amount recognized	(231)	(282)
United States | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Noncurrent assets	0	0
Current liabilities	(20)	(16)
Noncurrent liabilities	(269)	(337)
Net amount recognized	(289)	(353)
Non-U.S. | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Noncurrent assets	325	349
Current liabilities	(20)	(21)
Noncurrent liabilities	(615)	(631)
Net amount recognized	$ (310)	$ (303)