Derivative Financial Instruments (Location And Amounts Of Pre-Tax Gains (Losses) On Cash Flow Hedge Derivatives Financial Instruments) (Details) - Cash Flow Hedges [Member] - Designated as Hedging Instrument [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	$ 17	$ (71)
Cost Of Revenues [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	14	(59)
Selling, General and Administrative Expenses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	3	(12)
Foreign Exchange Forward Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
(Increase) Decrease in Derivative Losses Recognized in Accumulated Other Comprehensive Income (Loss) (effective portion)	$ 83	$ 17