Financial Instruments - Balance Sheet (Details) - USD ($) $ in Millions	6 Months Ended
Jun. 30, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Accumulated other comprehensive income (loss), cumulative changes in net gain (loss) from hedges, before tax	$ (5)	$ (14)
Gain (loss) expected to be reclassified in one year or less	(1)
Foreign currency
Derivatives, Fair Value [Line Items]
Accumulated other comprehensive income (loss), cumulative changes in net gain (loss) from hedges, before tax	(1)	0
Gain (loss) expected to be reclassified in one year or less	(1)
Designated as Hedging Instrument [Member] \| Foreign currency \| Prepaid Expenses and Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	2	2
Designated as Hedging Instrument [Member] \| Foreign currency \| Accounts Payable and Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	4	2
Not Designated as Hedging Instrument [Member] \| Foreign currency \| Prepaid Expenses and Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	1	1
Not Designated as Hedging Instrument [Member] \| Foreign currency \| Accounts Payable and Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	0	0
Net investment hedge \| Foreign currency
Derivatives, Fair Value [Line Items]
Accumulated other comprehensive income (loss), cumulative changes in net gain (loss) from hedges, before tax	4	4
Gain (loss) expected to be reclassified in one year or less	0
Net investment hedge \| Cross Currency Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Accumulated other comprehensive income (loss), cumulative changes in net gain (loss) from hedges, before tax	17	12
Gain (loss) expected to be reclassified in one year or less	0
Net investment hedge \| Foreign currency denominated debt designated as a net investment hedge [Member]
Derivatives, Fair Value [Line Items]
Accumulated other comprehensive income (loss), cumulative changes in net gain (loss) from hedges, before tax	(25)	(30)
Gain (loss) expected to be reclassified in one year or less	0
Net investment hedge \| Designated as Hedging Instrument [Member] \| Other Noncurrent Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	17	12
Net investment hedge \| Designated as Hedging Instrument [Member] \| Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	$ 0	$ 0

Accumulated other comprehensive income (loss), cumulative changes in net gain (loss) from hedges, before tax

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- Definition

The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

+ References

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- Definition

Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

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Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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