Fair Value Measurements (Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liability	$ (24)	$ (15)
Derivative Asset	12	6
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	13	9
Total liabilities	(25)	(18)
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	0	0
Total liabilities	0	0
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	13	9
Total liabilities	(25)	(18)
Other Noncurrent Liabilities [Member] | Fair Value, Measurements, Recurring [Member] | Designated as Hedging Instrument [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest Rate Cash Flow Hedge Liability at Fair Value	(21)	(10)
Other Noncurrent Liabilities [Member] | Fair Value, Measurements, Recurring [Member] | Designated as Hedging Instrument [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest Rate Cash Flow Hedge Liability at Fair Value	0	0
Other Noncurrent Liabilities [Member] | Fair Value, Measurements, Recurring [Member] | Designated as Hedging Instrument [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest Rate Cash Flow Hedge Liability at Fair Value	(21)	(10)
Current Other Assets [Member] | Fair Value, Measurements, Recurring [Member] | Not Designated as Hedging Instrument [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency forwards and swaps	4	8
Current Other Assets [Member] | Fair Value, Measurements, Recurring [Member] | Not Designated as Hedging Instrument [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency forwards and swaps	0	0
Current Other Assets [Member] | Fair Value, Measurements, Recurring [Member] | Not Designated as Hedging Instrument [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency forwards and swaps	4	8
Current Other liabilities [Member] | Fair Value, Measurements, Recurring [Member] | Not Designated as Hedging Instrument [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency forwards and swaps	(4)	(7)
Current Other liabilities [Member] | Fair Value, Measurements, Recurring [Member] | Not Designated as Hedging Instrument [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency forwards and swaps	0	0
Current Other liabilities [Member] | Fair Value, Measurements, Recurring [Member] | Not Designated as Hedging Instrument [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency forwards and swaps	(4)	(7)
Commodity Contract [Member] | Other Noncurrent Liabilities [Member] | Fair Value, Measurements, Recurring [Member] | Designated as Hedging Instrument [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liability		(1)
Commodity Contract [Member] | Other Noncurrent Liabilities [Member] | Fair Value, Measurements, Recurring [Member] | Designated as Hedging Instrument [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liability		0
Commodity Contract [Member] | Other Noncurrent Liabilities [Member] | Fair Value, Measurements, Recurring [Member] | Designated as Hedging Instrument [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liability		(1)
Commodity Contract [Member] | Current Other Assets [Member] | Fair Value, Measurements, Recurring [Member] | Designated as Hedging Instrument [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	7	1
Commodity Contract [Member] | Current Other Assets [Member] | Fair Value, Measurements, Recurring [Member] | Designated as Hedging Instrument [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	0	0
Commodity Contract [Member] | Current Other Assets [Member] | Fair Value, Measurements, Recurring [Member] | Designated as Hedging Instrument [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	7	$ 1
Commodity Contract [Member] | Other Noncurrent Assets [Member] | Fair Value, Measurements, Recurring [Member] | Designated as Hedging Instrument [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	2
Commodity Contract [Member] | Other Noncurrent Assets [Member] | Fair Value, Measurements, Recurring [Member] | Designated as Hedging Instrument [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	0
Commodity Contract [Member] | Other Noncurrent Assets [Member] | Fair Value, Measurements, Recurring [Member] | Designated as Hedging Instrument [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	$ 2