Derivative Instruments (Movements out of OCI) (Details) - Foreign currency exchange forward contracts - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Derivative [Line Items]
Foreign currency transaction gains (losses)	$ 9	$ 1	$ (15)
Cost of sales
Derivative [Line Items]
Foreign currency transaction gains (losses)	2	7	(6)
Designated as Hedging Instrument \| Other income (expense), net
Derivative [Line Items]
Foreign currency transaction gains (losses)	14	0	0
Not Designated as Hedging Instrument \| Other income (expense), net
Derivative [Line Items]
Foreign currency transaction gains (losses)	$ (7)	$ (6)	$ (9)

Amount before tax of foreign currency transaction realized and unrealized gain (loss) recognized in the income statement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 830
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6450222&loc=d3e30840-110895

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 830
-SubTopic 20
-Section 45
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 830
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=109240200&loc=d3e30690-110894

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