Pension, Other Postretirement Benefits and Savings Plans - Fair Values of Pension Plan Assets (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
United States
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	$ 4,780	$ 4,445
United States | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	4,031	3,425
United States | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	47	48
United States | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	3,980	3,375
United States | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	4	2
United States | Cash and short term securities
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	47	48
United States | Cash and short term securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	47	48
United States | Cash and short term securities | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
United States | Cash and short term securities | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
United States | Equity Securities, Common and Preferred Stock
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
United States | Equity Securities, Common and Preferred Stock | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
United States | Equity Securities, Common and Preferred Stock | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
United States | Equity Securities, Common and Preferred Stock | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
United States | Equity Securities, Commingled Funds
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
United States | Equity Securities, Commingled Funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
United States | Equity Securities, Commingled Funds | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
United States | Equity Securities, Commingled Funds | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
United States | Equity Securities, Commingled Funds | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	9	11
United States | Equity Securities, Mutual Funds
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
United States | Equity Securities, Mutual Funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
United States | Equity Securities, Mutual Funds | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
United States | Equity Securities, Mutual Funds | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
United States | Equity Securities, Mutual Funds | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
United States | Debt Securities, Corporate Bonds
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	2,577	2,344
United States | Debt Securities, Corporate Bonds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
United States | Debt Securities, Corporate Bonds | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	2,576	2,344
United States | Debt Securities, Corporate Bonds | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	1	0
United States | Debt Securities, Government Bonds
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	1,120	968
United States | Debt Securities, Government Bonds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
United States | Debt Securities, Government Bonds | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	1,120	968
United States | Debt Securities, Government Bonds | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
United States | Debt Securities, Repurchase Agreements
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
United States | Debt Securities, Repurchase Agreements | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
United States | Debt Securities, Repurchase Agreements | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
United States | Debt Securities, Repurchase Agreements | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
United States | Debt Securities, Asset-backed Securities
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	283	63
United States | Debt Securities, Asset-backed Securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
United States | Debt Securities, Asset-backed Securities | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	282	63
United States | Debt Securities, Asset-backed Securities | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	1	0
United States | Debt Securities, Commingled Funds | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	310	603
United States | Debt Securities, Mutual Funds
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
United States | Debt Securities, Mutual Funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
United States | Debt Securities, Mutual Funds | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
United States | Debt Securities, Mutual Funds | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
United States | Debt Securities, Mutual Funds | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	141	90
United States | Alternatives, Insurance Contracts
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	2	2
United States | Alternatives, Insurance Contracts | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
United States | Alternatives, Insurance Contracts | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
United States | Alternatives, Insurance Contracts | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	2	2
United States | Alternatives, Other Investments
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	2	0
United States | Alternatives, Other Investments | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
United States | Alternatives, Other Investments | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	2	0
United States | Alternatives, Other Investments | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
United States | Equity Securities, Partnership Interests | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	267	247
United States | Short Term Securities, Commingled Funds | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	67	59
United States | Alternatives, Commingled Funds | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
United States | Investments Before Other Plan Assets | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	4,825	4,435
United States | Other Assets | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	(45)	10
Non-U.S.
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	2,740	2,464
Non-U.S. | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	2,159	1,864
Non-U.S. | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	178	155
Non-U.S. | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	1,958	1,688
Non-U.S. | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	23	21
Non-U.S. | Cash and short term securities
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	33	29
Non-U.S. | Cash and short term securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	29	26
Non-U.S. | Cash and short term securities | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	4	3
Non-U.S. | Cash and short term securities | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
Non-U.S. | Equity Securities, Common and Preferred Stock
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	24	19
Non-U.S. | Equity Securities, Common and Preferred Stock | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	24	19
Non-U.S. | Equity Securities, Common and Preferred Stock | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
Non-U.S. | Equity Securities, Common and Preferred Stock | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
Non-U.S. | Equity Securities, Commingled Funds
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	36	14
Non-U.S. | Equity Securities, Commingled Funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	36	14
Non-U.S. | Equity Securities, Commingled Funds | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
Non-U.S. | Equity Securities, Commingled Funds | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
Non-U.S. | Equity Securities, Commingled Funds | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	69	56
Non-U.S. | Equity Securities, Mutual Funds
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	5	4
Non-U.S. | Equity Securities, Mutual Funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	5	4
Non-U.S. | Equity Securities, Mutual Funds | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
Non-U.S. | Equity Securities, Mutual Funds | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
Non-U.S. | Equity Securities, Mutual Funds | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	11	7
Non-U.S. | Debt Securities, Corporate Bonds
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	190	171
Non-U.S. | Debt Securities, Corporate Bonds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	10	17
Non-U.S. | Debt Securities, Corporate Bonds | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	180	154
Non-U.S. | Debt Securities, Corporate Bonds | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
Non-U.S. | Debt Securities, Government Bonds
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	2,271	2,158
Non-U.S. | Debt Securities, Government Bonds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	60	62
Non-U.S. | Debt Securities, Government Bonds | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	2,211	2,096
Non-U.S. | Debt Securities, Government Bonds | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
Non-U.S. | Debt Securities, Repurchase Agreements
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	(511)	(641)
Non-U.S. | Debt Securities, Repurchase Agreements | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
Non-U.S. | Debt Securities, Repurchase Agreements | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	(511)	(641)
Non-U.S. | Debt Securities, Repurchase Agreements | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
Non-U.S. | Debt Securities, Asset-backed Securities
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	74	67
Non-U.S. | Debt Securities, Asset-backed Securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	5	5
Non-U.S. | Debt Securities, Asset-backed Securities | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	69	62
Non-U.S. | Debt Securities, Asset-backed Securities | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
Non-U.S. | Debt Securities, Commingled Funds | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	604	638
Non-U.S. | Debt Securities, Mutual Funds
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	19	18
Non-U.S. | Debt Securities, Mutual Funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	9	8
Non-U.S. | Debt Securities, Mutual Funds | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	10	10
Non-U.S. | Debt Securities, Mutual Funds | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
Non-U.S. | Debt Securities, Mutual Funds | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	7	7
Non-U.S. | Alternatives, Insurance Contracts
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	22	19
Non-U.S. | Alternatives, Insurance Contracts | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
Non-U.S. | Alternatives, Insurance Contracts | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
Non-U.S. | Alternatives, Insurance Contracts | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	22	19
Non-U.S. | Alternatives, Other Investments
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	(4)	6
Non-U.S. | Alternatives, Other Investments | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
Non-U.S. | Alternatives, Other Investments | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	(5)	4
Non-U.S. | Alternatives, Other Investments | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	1	2
Non-U.S. | Equity Securities, Partnership Interests | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	0	0
Non-U.S. | Short Term Securities, Commingled Funds | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	4	7
Non-U.S. | Alternatives, Commingled Funds | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	6	5
Non-U.S. | Investments Before Other Plan Assets | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	2,860	2,584
Non-U.S. | Other Assets | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure [Line Items]
Total plan assets, fair value	$ (120)	$ (120)