Derivative Financial Instruments (Effect of Deriative Instruments on Income Statement and Statement of Comprehensive Income) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Derivative Financial Instruments
Amount of gain (loss) recognized in OCI	$ (4)	$ (6)	$ 7	$ (4)
Amount of gain reclassified from OCI into revenue	(1,351)	(1,160)	(2,607)	(2,283)
Reclassification out of Accumulated Other Comprehensive Income \| Foreign Exchange Contract
Derivative Financial Instruments
Amount of gain reclassified from OCI into revenue	1	(1)	(1)	1
Amount of (gain) loss reclassified from OCI into cost of revenue	0	1	(1)	2
Cash Flow Hedging [Member] \| Foreign Exchange Contract
Derivative Financial Instruments
Amount of gain (loss) recognized in OCI	4	6	(7)	4
Cash Flow Hedging [Member] \| Cross Currency Swaps
Derivative Financial Instruments
Amount of gain (loss) recognized in OCI	2	(22)	(32)	23
Cash Flow Hedging [Member] \| Foreign Currency Denominated Debt
Derivative Financial Instruments
Amount of gain (loss) recognized in OCI	(6)	(15)	20	(5)
Interest Expense \| Cross Currency Swaps
Derivative Financial Instruments
Amount of gain (loss) recognized in OCI	$ 5	$ 5	$ 10	$ 9

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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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).

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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.

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