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, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Net (Losses) Gains Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (effective portion)	$ (11)	$ 4	$ (14)	$ 0
Cost Of Revenues [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net (Losses) Gains Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (effective portion)	(9)	3	(12)	0
Selling, General and Administrative Expenses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net (Losses) Gains Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (effective portion)	(2)	1	(2)	0
Foreign Exchange Contract
Derivative Instruments, Gain (Loss) [Line Items]
Change in Derivative Gains Recognized in Accumulated Other Comprehensive Income (Loss) (effective portion)	$ 35	$ 19	$ (78)	$ 58