Financial Instruments (Schedule Of Effect Of Derivatives Recognized) (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Schedule of Cost-method Investments [Line Items]
Long-term Debt, Current Maturities	$ 26		$ 26		$ 279
Derivatives not designated as hedging instruments	(50)	$ 25	(67)	$ (4)
Interest Rate Swaps [Member]
Schedule of Cost-method Investments [Line Items]
Derivative, Notional Amount	1,800		1,800
Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member]
Schedule of Cost-method Investments [Line Items]
Interest rate swaps	(2)	(5)	(1)	(8)
Designated As Hedging Instruments [Member] | Foreign Exchange Contracts [Member]
Schedule of Cost-method Investments [Line Items]
Interest rate swaps	(26)	7	(31)	(7)
Not Designated As Hedging Instruments [Member] | Foreign Exchange Contracts [Member]
Schedule of Cost-method Investments [Line Items]
Derivatives not designated as hedging instruments	(21)	22	(33)	12
Not Designated As Hedging Instruments [Member] | Commodity Contracts [Member]
Schedule of Cost-method Investments [Line Items]
Derivatives not designated as hedging instruments	(1)	2	(2)	0
Not Designated As Hedging Instruments [Member] | Interest Rate Contracts [Member]
Schedule of Cost-method Investments [Line Items]
Derivatives not designated as hedging instruments	0	(1)	0	(1)
Operating Expense [Member]
Schedule of Cost-method Investments [Line Items]
Derivatives not designated as hedging instruments	10	4	15	23
Interest Expense [Member]
Schedule of Cost-method Investments [Line Items]
Derivatives not designated as hedging instruments	$ 11	$ 26	$ 18	$ 35