Effects of Cash Flow Hedges (Detail) (Cash Flow Hedges, USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Derivative Instruments, Gain (Loss) [Line Items]
Gains / (losses) reclassified from AOCI into earnings	$ 40	$ (53)	$ (312)
Gains / (losses) recognized in OCI	(79)	102	(75)
Gains / (losses) on ineffectiveness recognized in earnings	(10)	1	(26)
Currency exchange contracts \| Forecasted transactions
Derivative Instruments, Gain (Loss) [Line Items]
Gains / (losses) reclassified from AOCI into earnings	26	(26)	58
Gains / (losses) recognized in OCI	82	(23)	(16)
Commodity contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gains / (losses) reclassified from AOCI into earnings	16	(23)	(10)
Gains / (losses) recognized in OCI	(2)	3	(24)
Gains / (losses) on ineffectiveness recognized in earnings	(10)	1	(3)
Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gains / (losses) reclassified from AOCI into earnings	(2)	(4)	(360)
Gains / (losses) recognized in OCI	(159)	122	(35)
Gains / (losses) on ineffectiveness recognized in earnings			$ (23)

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The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4C

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624171-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4D

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624177-113959

+ Details

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- Definition

The effective portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments that was recognized in other comprehensive income during the current period.

+ References

+ Details

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- Definition

The net gain (loss) recognized in earnings during the reporting period representing the amount of the cash flow hedges' ineffectiveness.

+ References

+ Details

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