Hedges and Derivative Financial Instruments - Schedule of Outstanding Derivative Contracts (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Mar. 31, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Fair value of hedged assets	$ 103	$ 77
Fair value of hedged liabilities	94	144
Derivative asset at fair value, current	65	60
Derivative asset at fair value, noncurrent	38	17
Total derivatives, hedge assets at fair value	103	77
Derivative liability at fair value, current	38	95
Derivative liability at fair value, noncurrent	56	49
Total derivatives, hedge liabilities at fair value	94	144
Derivatives accounted for as hedges
Derivatives, Fair Value [Line Items]
Fair value of hedged assets	72	50
Fair value of hedged liabilities	77	75
Derivatives accounted for as hedges \| Foreign exchange forwards/options
Derivatives, Fair Value [Line Items]
Notional Amount	3,012	3,126
Fair value of hedged assets	47	49
Fair value of hedged liabilities	$ 34	$ 48
Maximum term of foreign exchange forwards/options	41 months	44 months
Derivatives accounted for as hedges \| Commodity swaps/options
Derivatives, Fair Value [Line Items]
Notional Amount	$ 243	$ 216
Fair value of hedged assets	11	1
Fair value of hedged liabilities	$ 12	$ 27
Maximum term of commodity swaps/options	27 months	30 months
Derivatives accounted for as hedges \| Interest rate derivatives
Derivatives, Fair Value [Line Items]
Notional Amount	$ 700	$ 0
Fair value of hedged assets	14	0
Fair value of hedged liabilities	$ 31	$ 0
Maximum term of commodity swaps/options	119 months	0 months
Derivatives not accounted for as hedges
Derivatives, Fair Value [Line Items]
Fair value of hedged assets	$ 31	$ 27
Fair value of hedged liabilities	17	69
Derivatives not accounted for as hedges \| Foreign exchange forwards/options
Derivatives, Fair Value [Line Items]
Notional Amount	3,061	4,382
Fair value of hedged assets	30	27
Fair value of hedged liabilities	$ 16	$ 69
Maximum term of foreign exchange forwards/options	18 months	21 months
Derivatives not accounted for as hedges \| Commodity swaps/options
Derivatives, Fair Value [Line Items]
Notional Amount	$ 36	$ 3
Fair value of hedged assets	1	0
Fair value of hedged liabilities	$ 1	$ 0
Maximum term of commodity swaps/options	27 months	0 months

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

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