Derivative Financial Instruments (Location And Amounts Of Pre-Tax Gains (Losses) On Cash Flow Hedge Derivatives Financial Instruments) (Details) - Cash Flow Hedging [Member] - Designated as Hedging Instrument [Member] - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Derivative Instruments, Gain (Loss) [Line Items]
Net Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (effective portion)	$ 14	$ (11)	$ 35	$ (14)
Cost Of Revenues [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (effective portion)	12	(9)	30	(12)
Selling, General and Administrative Expenses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (effective portion)	2	(2)	5	(2)
Foreign Exchange Contract
Derivative Instruments, Gain (Loss) [Line Items]
Change in Derivative (Losses) Gains Recognized in Accumulated Other Comprehensive Income (Loss) (effective portion)	$ (3)	$ 35	$ 14	$ (78)