Pensions Benefit Plans and Other Postretirement Benefits - U.S. Plan Assets By Hierarchy (Details) - Pension Benefit Plans - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Minimum
Defined Benefit Plan Disclosure
Defined Benefit Plan, Target Plan Asset Allocations	10.00%
Level 3
Defined Benefit Plan Disclosure
Plan assets at fair value			$ 10
U.S.
Defined Benefit Plan Disclosure
Plan assets at fair value	$ 1,094	$ 1,394	1,654
U.S. | Equity securities
Defined Benefit Plan Disclosure
Defined Benefit Plan, Target Plan Asset Allocations	62.00%
U.S. | Debt securities
Defined Benefit Plan Disclosure
Defined Benefit Plan, Target Plan Asset Allocations	32.00%
U.S. | Real estate and other
Defined Benefit Plan Disclosure
Defined Benefit Plan, Target Plan Asset Allocations	6.00%
Non-U.S.
Defined Benefit Plan Disclosure
Plan assets at fair value	$ 843	975	$ 1,011
Investments measured at net asset value	763	906
Non-U.S. | Cash and cash equivalents
Defined Benefit Plan Disclosure
Plan assets at fair value	$ 9	9
Non-U.S. | Equity securities
Defined Benefit Plan Disclosure
Defined Benefit Plan, Target Plan Asset Allocations	16.00%
Non-U.S. | Debt securities
Defined Benefit Plan Disclosure
Plan assets at fair value	$ 41	33
Defined Benefit Plan, Target Plan Asset Allocations	60.00%
Non-U.S. | Other
Defined Benefit Plan Disclosure
Plan assets at fair value	$ 30	27
Non-U.S. | Real estate and other
Defined Benefit Plan Disclosure
Defined Benefit Plan, Target Plan Asset Allocations	24.00%
Non-U.S. | Level 1
Defined Benefit Plan Disclosure
Plan assets at fair value	$ 43	42
Non-U.S. | Level 1 | Cash and cash equivalents
Defined Benefit Plan Disclosure
Plan assets at fair value	9	9
Non-U.S. | Level 1 | Debt securities
Defined Benefit Plan Disclosure
Plan assets at fair value	34	33
Non-U.S. | Level 2
Defined Benefit Plan Disclosure
Plan assets at fair value	37	27
Non-U.S. | Level 2 | Debt securities
Defined Benefit Plan Disclosure
Plan assets at fair value	7
Non-U.S. | Level 2 | Other
Defined Benefit Plan Disclosure
Plan assets at fair value	$ 30	$ 27