Derivatives and Hedging Activities - Fair Values, Volume of Activity and Gain (Loss) Information Related to Derivative Instruments (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Derivatives, Fair Value [Line Items]
Notional Amount	$ 65,317invest_DerivativeNotionalAmount	$ 68,077invest_DerivativeNotionalAmount
Derivative Assets	454	335
Derivative Liabilities	543	127
Derivative Asset, Netting adjustments	(1,034)	(812)
Derivative Liability, Netting adjustments	(542)	(500)
Derivatives Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	15,466	14,677
Derivative assets	280	310
Derivative liabilities	26	38
Derivatives Not Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	49,851	53,400
Derivative assets	1,363	909
Derivative liabilities	1,300	876
Interest Rate [Member] \| Derivatives Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	15,095	14,487
Derivative assets	272	306
Derivative liabilities	26	37
Interest Rate [Member] \| Derivatives Not Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	43,771	46,173
Derivative assets	665	733
Derivative liabilities	618	702
Foreign Exchange [Member] \| Derivatives Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	371	190
Derivative assets	8	4
Derivative liabilities		1
Foreign Exchange [Member] \| Derivatives Not Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	4,024	4,701
Derivative assets	85	59
Derivative liabilities	81	56
Commodity [Member] \| Derivatives Not Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	1,544	1,616
Derivative assets	608	112
Derivative liabilities	594	106
Credit [Member] \| Derivatives Not Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	512	910
Derivative assets	5	5
Derivative liabilities	7	12
Net Derivatives [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	65,317	68,077
Derivative Assets	609	407
Derivative Liabilities	784	414
Other Collateral [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	(155)	(72)
Derivative Liabilities	$ (241)	$ (287)

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 12

-Section 13

-Sentence Column B

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Amount of obligation to return cash collateral under master netting arrangements offset against derivative assets.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 45

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958

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

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Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 20

-Section 50

-Paragraph 3

-Subparagraph (a)

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

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

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

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Amount of right to receive cash collateral under master netting arrangements offset against derivative liabilities.

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