Fair Value (Quantitative Information) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Fair Value Inputs Quantitative Information [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs	$ 14	$ 63	$ 99	$ 93
Interest Rate Contract [Member]
Fair Value Inputs Quantitative Information [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs	(182)	(140)	(129)	(151)
Foreign Exchange Contract [Member]
Fair Value Inputs Quantitative Information [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs	194	199	225	240
Commodity Contract [Member]
Fair Value Inputs Quantitative Information [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs	2	$ 4	$ 3	$ 4
Argentina, Pesos | Foreign Exchange Contract [Member]
Fair Value Inputs Quantitative Information [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs	$ 194
Argentina, Pesos | Foreign Exchange Contract [Member] | Minimum [Member]
Fair Value Derivative Assets Liabilities Measured On Recurring Basis Unobservable Inputs [Abstract]
Derivative, Forward Exchange Rate	0.5700
Argentina, Pesos | Foreign Exchange Contract [Member] | Maximum [Member]
Fair Value Derivative Assets Liabilities Measured On Recurring Basis Unobservable Inputs [Abstract]
Derivative, Forward Exchange Rate	1.0500
Argentina, Pesos | Foreign Exchange Contract [Member] | Weighted Average [Member]
Fair Value Derivative Assets Liabilities Measured On Recurring Basis Unobservable Inputs [Abstract]
Derivative, Forward Exchange Rate	0.8500
Measurement Input, Entity Credit Risk [Member] | Interest Rate Contract [Member] | Minimum [Member]
Fair Value Inputs Quantitative Information [Line Items]
Fair Value Measurement Inputs, Nonrecurring	2.00%
Measurement Input, Entity Credit Risk [Member] | Interest Rate Contract [Member] | Maximum [Member]
Fair Value Inputs Quantitative Information [Line Items]
Fair Value Measurement Inputs, Nonrecurring	4.43%
Measurement Input, Entity Credit Risk [Member] | Interest Rate Contract [Member] | Weighted Average [Member]
Fair Value Inputs Quantitative Information [Line Items]
Fair Value Measurement Inputs, Nonrecurring	4.00%