Accumulated Other Comprehensive Income (Loss) (AOCI) - Changes in AOCI by Component (Details) $ in Millions	3 Months Ended
Mar. 31, 2019 USD ($)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance as of December 31, 2018	$ (246)
Other comprehensive income (loss) before reclassifications	20
Amounts reclassified from AOCI	(4)
Net current period other comprehensive (loss) income	16
Balance as of March 31, 2019	(230)
Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance as of December 31, 2018	(234)
Other comprehensive income (loss) before reclassifications	19
Amounts reclassified from AOCI	0
Net current period other comprehensive (loss) income	19
Balance as of March 31, 2019	(215)
Changes in Employee Benefit Plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance as of December 31, 2018	(14)
Other comprehensive income (loss) before reclassifications	0
Amounts reclassified from AOCI	(3)
Net current period other comprehensive (loss) income	(3)
Balance as of March 31, 2019	(17)
Changes in Fair Value of Effective Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance as of December 31, 2018	2
Other comprehensive income (loss) before reclassifications	1
Amounts reclassified from AOCI	(1)
Net current period other comprehensive (loss) income	0
Balance as of March 31, 2019	$ 2

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

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Amount after tax, before reclassification adjustments of other comprehensive income (loss).

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Amount after tax of other comprehensive income (loss) attributable to parent entity.

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Amount after tax of reclassification adjustments of other comprehensive income (loss).

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