Derivative Financial Instruments - Gain or Loss Recorded on Derivatives Related to Fair Value Option Debt Primarily Due to Changes in Interest Rates (Detail) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2017	Mar. 31, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Total amount of Gain (loss) recognized in derivative related income (expense)	$ (6)	$ 7
Cross currency interest rate contracts [Member] \| Gain (loss) on debt designated at fair value and related derivatives [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Currency contracts, Gain (loss) on debt designated at fair value and related derivatives, Amount of Gain (Loss) Recognized in Derivative Related Income (Expense)	$ (6)	$ 7

Amount of gain (loss) from the increase (decrease) in fair value of foreign currency derivatives and nonderivative instruments designated as fair value hedging instruments which were recognized in earnings, net of offsets by the gain (loss) on the hedged item to the extent that the fair value hedge was determined to be effective.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5618551-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624171-113959

Name:	us-gaap_GainLossOnForeignCurrencyFairValueHedgeDerivatives
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration