Fair Value (Quantitative Information) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Fair Value Inputs Quantitative Information [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs		$ (102)	$ 63	$ 93
Foreign Exchange Contract [Member]
Fair Value Inputs Quantitative Information [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs		94	199	240
Interest Rate Contract
Fair Value Inputs Quantitative Information [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs		(184)	(140)	(151)
Cross Currency Interest Rate Contract [Member]
Fair Value Inputs Quantitative Information [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs		(11)	0	0
Commodity Contract [Member]
Fair Value Inputs Quantitative Information [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs		$ (1)	$ 4	$ 4
Measurement Input, Entity Credit Risk [Member] | Interest Rate Contract | Minimum
Fair Value Inputs Quantitative Information [Line Items]
Fair Value Measurement Inputs, Nonrecurring	0.80%
Measurement Input, Entity Credit Risk [Member] | Interest Rate Contract | Maximum
Fair Value Inputs Quantitative Information [Line Items]
Fair Value Measurement Inputs, Nonrecurring	4.94%
Measurement Input, Entity Credit Risk [Member] | Interest Rate Contract | Weighted Average
Fair Value Inputs Quantitative Information [Line Items]
Fair Value Measurement Inputs, Nonrecurring	3.70%
Measurement Input, Entity Credit Risk [Member] | Cross Currency Interest Rate Contract [Member] | Weighted Average
Fair Value Inputs Quantitative Information [Line Items]
Fair Value Measurement Inputs, Nonrecurring	2.10%