Financial Instruments (Fair Values Of Derivatives Instruments) (Detail) - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
Schedule of Cost-method Investments [Line Items]
Fair Value, Asset Derivatives	$ 7	$ 15
Fair Value, Liability Derivatives	32	13
Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member]
Schedule of Cost-method Investments [Line Items]
Fair Value, Asset Derivatives	4	7
Fair Value, Liability Derivatives	2	4
Not Designated As Hedging Instruments [Member] | Foreign Exchange Contract [Member]
Schedule of Cost-method Investments [Line Items]
Fair Value, Asset Derivatives	2	7
Fair Value, Liability Derivatives	26	2
Not Designated As Hedging Instruments [Member] | Interest Rate Contracts [Member]
Schedule of Cost-method Investments [Line Items]
Fair Value, Asset Derivatives	1	1
Fair Value, Liability Derivatives	2	7
Not Designated As Hedging Instruments [Member] | Commodity Contracts [Member]
Schedule of Cost-method Investments [Line Items]
Fair Value, Asset Derivatives	0	0
Fair Value, Liability Derivatives	$ 2	$ 0