Hedges and Derivative Financial Instruments - Schedule of Outstanding Derivative Contracts (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
Sep. 30, 2018	Dec. 31, 2017
Derivatives, Fair Value [Line Items]
Fair value of hedged assets	$ 53	$ 142
Fair value of hedged liabilities	125	208
Derivative asset at fair value, current	39	89
Derivative asset at fair value, noncurrent	14	53
Total derivatives, hedge assets at fair value	53	142
Derivative liability at fair value, current	72	81
Derivative liability at fair value, noncurrent	53	127
Total derivatives, hedge liabilities at fair value	125	208
Derivatives accounted for as hedges
Derivatives, Fair Value [Line Items]
Fair value of hedged assets	32	84
Fair value of hedged liabilities	76	158
Derivatives accounted for as hedges \| Foreign exchange forwards/options
Derivatives, Fair Value [Line Items]
Notional Amount	3,218	3,113
Fair value of hedged assets	27	55
Fair value of hedged liabilities	$ 56	$ 157
Maximum term of foreign exchange forwards/options	47 months	56 months
Derivatives accounted for as hedges \| Commodity swaps/options
Derivatives, Fair Value [Line Items]
Notional Amount	$ 234	$ 269
Fair value of hedged assets	5	29
Fair value of hedged liabilities	$ 18	$ 1
Maximum term of commodity swaps/options	33 months	36 months
Derivatives accounted for as hedges \| Interest rate derivatives
Derivatives, Fair Value [Line Items]
Notional Amount	$ 350	$ 0
Fair value of hedged assets	0	0
Fair value of hedged liabilities	$ 2	$ 0
Maximum term of commodity swaps/options	2 months	0 months
Derivatives not accounted for as hedges
Derivatives, Fair Value [Line Items]
Fair value of hedged assets	$ 21	$ 58
Fair value of hedged liabilities	49	50
Derivatives not accounted for as hedges \| Foreign exchange forwards/options
Derivatives, Fair Value [Line Items]
Notional Amount	4,037	3,390
Fair value of hedged assets	21	58
Fair value of hedged liabilities	$ 49	$ 50
Maximum term of foreign exchange forwards/options	24 months	33 months
Derivatives not accounted for as hedges \| Commodity swaps/options
Derivatives, Fair Value [Line Items]
Notional Amount	$ 0	$ 1
Fair value of hedged assets	0	0
Fair value of hedged liabilities	$ 0	$ 0
Maximum term of commodity swaps/options	0 months	5 months

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

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