Derivative Financial Instruments (Effect of Deriative Instruments on Income Statement and Statement of Comprehensive Income) (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Derivative Financial Instruments
Amount of gain (loss) recognized in OCI	$ 2	$ 9
Amount of gain reclassified from OCI into revenue	(1,123)	(1,237)
Reclassification out of Accumulated Other Comprehensive Income \| Foreign Exchange Contract
Derivative Financial Instruments
Amount of gain reclassified from OCI into revenue	2	1
Amount of (gain) loss reclassified from OCI into cost of revenue	1	1
Cash Flow Hedging [Member] \| Foreign Exchange Contract
Derivative Financial Instruments
Amount of gain (loss) recognized in OCI	(2)	(9)
Cash Flow Hedging [Member] \| Cross Currency Swaps
Derivative Financial Instruments
Amount of gain (loss) recognized in OCI	45	7
Cash Flow Hedging [Member] \| Foreign Currency Denominated Debt
Derivative Financial Instruments
Amount of gain (loss) recognized in OCI	10	7
Interest Expense \| Cross Currency Swaps
Derivative Financial Instruments
Amount of gain (loss) recognized in OCI	$ 4	$ 3

The aggregate costs related to goods produced and sold and services rendered by an entity during the reporting period. This excludes costs incurred during the reporting period related to financial services rendered and other revenue generating activities.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.2(a),(d))
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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
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-Section 50
-Paragraph 32
-Subparagraph (a)
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
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-Section 50
-Paragraph 22
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(1))
-URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227

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- Definition

Amount of net unrealized gain (loss) related to the change in fair value of foreign currency exchange rate derivatives designated as cash flow hedging instruments. Recorded in accumulated other comprehensive income to the extent that the cash flow hedge is determined to be effective.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624171-113959

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- Definition

Derivative instruments gains losses in statement of financial performance.

+ References

No definition available.

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