Pensions FV Assets (Details) - Pension Plans, Defined Benefit [Member] - USD ($) $ in Millions		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
United States
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		$ 1,091	$ 1,181	$ 944
United States | Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	[1]	$ 1,091	1,181
United States | U.S. Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		10.00%
Fair Value of Plan Assets		$ 104	163
United States | U.S. Equity Funds [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	[1]	$ 104	163
United States | International Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		10.00%
Fair Value of Plan Assets		$ 103	180
United States | International Equity Funds [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	[1]	$ 103	180
United States | Fixed Income Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		80.00%
Fair Value of Plan Assets		$ 868	761
United States | Fixed Income Funds [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	[1]	868	761
United States | Private Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets			2
United States | Private Equity Funds [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	[1]		2
United States | Money Market Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		16	75
United States | Money Market Funds [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	[1]	$ 16	75
United States | Maximum [Member] | Private Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		1.00%
Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		$ 932	1,011	$ 853
Foreign Plan [Member] | Quoted Prices in Active Markets (Level I) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		5	40
Foreign Plan [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		237	202
Foreign Plan [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	[1]	690	769
Foreign Plan [Member] | Fixed Income Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		299	312
Foreign Plan [Member] | Fixed Income Funds [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	[1]	299	312
Foreign Plan [Member] | Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		43	75
Foreign Plan [Member] | Equity Funds [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	[1]	43	75
Foreign Plan [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		61	77
Foreign Plan [Member] | Hedge Funds [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	[1]	61	77
Foreign Plan [Member] | Multi-asset Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		97	79
Foreign Plan [Member] | Multi-asset Funds [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	[1]	97	79
Foreign Plan [Member] | Alternative Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		20	17
Foreign Plan [Member] | Alternative Investments [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	[1]	20	17
Foreign Plan [Member] | Derivative Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		169	194
Foreign Plan [Member] | Derivative Funds [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	[1]	169	194
Foreign Plan [Member] | Insurance Contracts [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		237	202
Foreign Plan [Member] | Insurance Contracts [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		237	202
Foreign Plan [Member] | Cash / Money Market Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		6	55
Foreign Plan [Member] | Cash / Money Market Funds [Member] | Quoted Prices in Active Markets (Level I) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		5	40
Foreign Plan [Member] | Cash / Money Market Funds [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	[1]	$ 1	$ 15
Foreign Plan [Member] | Minimum [Member] | Fixed Income Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		0.00%
Foreign Plan [Member] | Minimum [Member] | Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		0.00%
Foreign Plan [Member] | Minimum [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		0.00%
Foreign Plan [Member] | Minimum [Member] | Multi-asset Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		0.00%
Foreign Plan [Member] | Minimum [Member] | Alternative Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		0.00%
Foreign Plan [Member] | Minimum [Member] | Derivative Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		0.00%
Foreign Plan [Member] | Maximum [Member] | Fixed Income Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		55.00%
Foreign Plan [Member] | Maximum [Member] | Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		25.00%
Foreign Plan [Member] | Maximum [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		20.00%
Foreign Plan [Member] | Maximum [Member] | Multi-asset Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		100.00%
Foreign Plan [Member] | Maximum [Member] | Alternative Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		15.00%
Foreign Plan [Member] | Maximum [Member] | Derivative Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		22.00%

[1] Investments measured at the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy.