Employee Benefit Plans - Defined Benefit Plans Assets Measured at Fair Value (Details) - Pension Plan - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	$ 8,878	$ 8,087
Assets measured at NAV | Mutual Fund
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	76
U.S.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	$ 2,493	$ 2,358	$ 3,224
Defined benefit plan, plan assets, allocation (percent)	100.00%	100.00%
U.S. | Cash and cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	$ 9	$ 1
U.S. | U.S.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	221	117
U.S. | International
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	384	149
U.S. | U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	316	248
U.S. | Debt security issued by government agency
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	67	81
U.S. | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	1,119	1,363
U.S. | Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	45	(26)
U.S. | Real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	$ 15	$ 28
Defined benefit plan, plan assets, allocation (percent)	6.00%	3.00%
U.S. | Private equity/venture capital
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	$ 199	$ 353
Defined benefit plan, plan assets, allocation (percent)	8.00%	6.00%
U.S. | Guaranteed insurance contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	$ 0	$ 0
U.S. | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	$ 118	$ 44
Defined benefit plan, plan assets, allocation (percent)	2.00%	6.00%
U.S. | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	$ 348	$ 211
U.S. | Level 1 | Cash and cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	9	1
U.S. | Level 1 | U.S.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	182	82
U.S. | Level 1 | International
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	193	97
U.S. | Level 1 | U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
U.S. | Level 1 | Debt security issued by government agency
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
U.S. | Level 1 | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
U.S. | Level 1 | Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
U.S. | Level 1 | Real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	19
U.S. | Level 1 | Private equity/venture capital
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
U.S. | Level 1 | Guaranteed insurance contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
U.S. | Level 1 | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	(36)	12
Plan assets, non-financial, amount	(36)	12
U.S. | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	1,547	1,666
U.S. | Level 2 | Cash and cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
U.S. | Level 2 | U.S.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
U.S. | Level 2 | International
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
U.S. | Level 2 | U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	316	248
U.S. | Level 2 | Debt security issued by government agency
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	67	81
U.S. | Level 2 | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	1,119	1,363
U.S. | Level 2 | Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	45	(26)
U.S. | Level 2 | Real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
U.S. | Level 2 | Private equity/venture capital
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
U.S. | Level 2 | Guaranteed insurance contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
U.S. | Level 2 | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
U.S. | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	5	0
U.S. | Level 3 | Cash and cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
U.S. | Level 3 | U.S.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
U.S. | Level 3 | International
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
U.S. | Level 3 | U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
U.S. | Level 3 | Debt security issued by government agency
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
U.S. | Level 3 | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
U.S. | Level 3 | Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
U.S. | Level 3 | Real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	5	0	0
U.S. | Level 3 | Private equity/venture capital
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
U.S. | Level 3 | Guaranteed insurance contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
U.S. | Level 3 | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
U.S. | Assets measured at NAV
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	593	481
U.S. | Assets measured at NAV | Cash and cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
U.S. | Assets measured at NAV | U.S.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	39	35
U.S. | Assets measured at NAV | International
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	191	52
U.S. | Assets measured at NAV | U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
U.S. | Assets measured at NAV | Debt security issued by government agency
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
U.S. | Assets measured at NAV | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
U.S. | Assets measured at NAV | Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
U.S. | Assets measured at NAV | Real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	10	9
U.S. | Assets measured at NAV | Private equity/venture capital
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	199	353
U.S. | Assets measured at NAV | Guaranteed insurance contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
U.S. | Assets measured at NAV | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	154	32
Foreign Plan
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	$ 6,385	$ 5,729	6,308
Defined benefit plan, plan assets, allocation (percent)	100.00%	100.00%
Foreign Plan | Cash and cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	$ 421	$ 370
Foreign Plan | U.S.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	184	145
Foreign Plan | International
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	882	582
Foreign Plan | U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	47	57
Foreign Plan | Debt security issued by government agency
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	1,825	1,861
Foreign Plan | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	841	736
Foreign Plan | Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	186	99
Foreign Plan | Real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	$ 335	$ 367
Defined benefit plan, plan assets, allocation (percent)	5.00%	6.00%
Foreign Plan | Private equity/venture capital
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	$ 1,532	$ 1,392
Defined benefit plan, plan assets, allocation (percent)	24.00%	24.00%
Foreign Plan | Guaranteed insurance contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	$ 90	$ 92
Foreign Plan | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	$ 42	$ 28
Defined benefit plan, plan assets, allocation (percent)	11.00%	11.00%
Foreign Plan | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	$ 1,026	$ 837
Foreign Plan | Level 1 | Cash and cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	421	370
Foreign Plan | Level 1 | U.S.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	132	103
Foreign Plan | Level 1 | International
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	462	359
Foreign Plan | Level 1 | U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
Foreign Plan | Level 1 | Debt security issued by government agency
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
Foreign Plan | Level 1 | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
Foreign Plan | Level 1 | Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
Foreign Plan | Level 1 | Real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
Foreign Plan | Level 1 | Private equity/venture capital
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
Foreign Plan | Level 1 | Guaranteed insurance contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
Foreign Plan | Level 1 | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	11	5
Plan assets, non-financial, amount	11	5
Foreign Plan | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	3,284	2,929
Foreign Plan | Level 2 | Cash and cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
Foreign Plan | Level 2 | U.S.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	52	42
Foreign Plan | Level 2 | International
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	302	111
Foreign Plan | Level 2 | U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	47	57
Foreign Plan | Level 2 | Debt security issued by government agency
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	1,825	1,861
Foreign Plan | Level 2 | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	841	736
Foreign Plan | Level 2 | Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	186	99
Foreign Plan | Level 2 | Real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
Foreign Plan | Level 2 | Private equity/venture capital
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
Foreign Plan | Level 2 | Guaranteed insurance contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
Foreign Plan | Level 2 | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	31	23
Foreign Plan | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	314	308	244
Foreign Plan | Level 3 | Cash and cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
Foreign Plan | Level 3 | U.S.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
Foreign Plan | Level 3 | International
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
Foreign Plan | Level 3 | U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
Foreign Plan | Level 3 | Debt security issued by government agency
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
Foreign Plan | Level 3 | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
Foreign Plan | Level 3 | Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
Foreign Plan | Level 3 | Real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	219	210	137
Foreign Plan | Level 3 | Private equity/venture capital
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	5	6
Foreign Plan | Level 3 | Guaranteed insurance contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	90	92	$ 100
Foreign Plan | Level 3 | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
Foreign Plan | Assets measured at NAV
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	1,761	1,655
Foreign Plan | Assets measured at NAV | Cash and cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
Foreign Plan | Assets measured at NAV | U.S.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
Foreign Plan | Assets measured at NAV | International
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	118	112
Foreign Plan | Assets measured at NAV | U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
Foreign Plan | Assets measured at NAV | Debt security issued by government agency
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
Foreign Plan | Assets measured at NAV | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
Foreign Plan | Assets measured at NAV | Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
Foreign Plan | Assets measured at NAV | Real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	116	157
Foreign Plan | Assets measured at NAV | Private equity/venture capital
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	1,527	1,386
Foreign Plan | Assets measured at NAV | Guaranteed insurance contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	0	0
Foreign Plan | Assets measured at NAV | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plan assets, amount	$ 0	$ 0
Fixed Income Securities | Assets measured at NAV | Mutual Fund
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Defined benefit plan, plan assets, allocation (percent)	75.00%
Equity Securities | Assets measured at NAV | Mutual Fund
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Defined benefit plan, plan assets, allocation (percent)	25.00%