Financial Instruments (Schedule Of Effect Of Derivatives Recognized) (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Schedule of Cost-method Investments [Line Items]
Long-term Debt, Current Maturities	$ 474		$ 279
Derivatives not designated as hedging instruments	(17)	$ (29)
Interest Rate Swaps [Member]
Schedule of Cost-method Investments [Line Items]
Derivative, Notional Amount	2,050
Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member]
Schedule of Cost-method Investments [Line Items]
Interest rate swaps	1	(3)
Designated As Hedging Instruments [Member] | Foreign Exchange Contracts [Member]
Schedule of Cost-method Investments [Line Items]
Interest rate swaps	(5)	(14)
Not Designated As Hedging Instruments [Member] | Foreign Exchange Contracts [Member]
Schedule of Cost-method Investments [Line Items]
Derivatives not designated as hedging instruments	(12)	(10)
Not Designated As Hedging Instruments [Member] | Commodity Contracts [Member]
Schedule of Cost-method Investments [Line Items]
Derivatives not designated as hedging instruments	(1)	(2)
Operating Expense [Member]
Schedule of Cost-method Investments [Line Items]
Derivatives not designated as hedging instruments	$ 5	$ 19