Derivatives - BS Location (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Location and Fair Value Amount of Derivative Instruments
Fair Value of Derivative Instruments, Assets	$ 171	$ 146
Fair Value of Derivative Instruments, Liabilities	56	53
Derivatives designated as hedging instruments
Location and Fair Value Amount of Derivative Instruments
Fair Value of Derivative Instruments, Assets	160	132
Fair Value of Derivative Instruments, Liabilities	44	47
Derivatives designated as hedging instruments \| Foreign currency forward/option contracts \| Other current assets
Location and Fair Value Amount of Derivative Instruments
Fair Value of Derivative Instruments, Assets	88	74
Derivatives designated as hedging instruments \| Foreign currency forward/option contracts \| Other assets
Location and Fair Value Amount of Derivative Instruments
Fair Value of Derivative Instruments, Assets	53	39
Derivatives designated as hedging instruments \| Foreign currency forward/option contracts \| Other current liabilities
Location and Fair Value Amount of Derivative Instruments
Fair Value of Derivative Instruments, Liabilities	11	12
Derivatives designated as hedging instruments \| Foreign currency forward/option contracts \| Other liabilities
Location and Fair Value Amount of Derivative Instruments
Fair Value of Derivative Instruments, Liabilities	1	4
Derivatives designated as hedging instruments \| Foreign currency forward/option contracts \| Current balance sheet location
Location and Fair Value Amount of Derivative Instruments
Derivative Notional Amount	2,742	2,277
Derivatives designated as hedging instruments \| Foreign currency forward/option contracts \| Noncurrent balance sheet location
Location and Fair Value Amount of Derivative Instruments
Derivative Notional Amount	1,100	1,099
Derivatives designated as hedging instruments \| Interest rate swap contracts \| Other assets
Location and Fair Value Amount of Derivative Instruments
Fair Value of Derivative Instruments, Assets	19	19
Derivatives designated as hedging instruments \| Interest rate swap contracts \| Other current liabilities
Location and Fair Value Amount of Derivative Instruments
Fair Value of Derivative Instruments, Liabilities	1	14
Derivatives designated as hedging instruments \| Interest rate swap contracts \| Other liabilities
Location and Fair Value Amount of Derivative Instruments
Fair Value of Derivative Instruments, Liabilities	31	17
Derivatives designated as hedging instruments \| Interest rate swap contracts \| Current balance sheet location
Location and Fair Value Amount of Derivative Instruments
Derivative Notional Amount	600	1,000
Derivatives designated as hedging instruments \| Interest rate swap contracts \| Noncurrent balance sheet location
Location and Fair Value Amount of Derivative Instruments
Derivative Notional Amount	1,453	1,403
Derivatives not designated as hedging instruments
Location and Fair Value Amount of Derivative Instruments
Fair Value of Derivative Instruments, Assets	11	14
Fair Value of Derivative Instruments, Liabilities	12	6
Derivatives not designated as hedging instruments \| Foreign currency forward/option contracts \| Other current assets
Location and Fair Value Amount of Derivative Instruments
Fair Value of Derivative Instruments, Assets	11	14
Derivatives not designated as hedging instruments \| Foreign currency forward/option contracts \| Other current liabilities
Location and Fair Value Amount of Derivative Instruments
Fair Value of Derivative Instruments, Liabilities	12	6
Derivatives not designated as hedging instruments \| Foreign currency forward/option contracts \| Current balance sheet location
Location and Fair Value Amount of Derivative Instruments
Derivative Notional Amount	$ 2,925	$ 2,484

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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

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+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226000-175313

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4D
-Subparagraph (c)(2)
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
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-SubTopic 10
-Section 50
-Paragraph 4B
-Subparagraph (a),(c)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624163-113959

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Section 50
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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