Impairment related to private capital investment.

No definition available.

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- Definition

Number of low income housing credit investments.

+ References

No definition available.

+ Details

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- Definition

Other noninterest expenses that are not separately presented in any other noninterest expense category.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-04.14)

-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

+ Details

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- Definition

The carrying amount of the consolidated Variable Interest Entity's assets included in the reporting entity's statement of financial position.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (bb)

-URI http://asc.fasb.org/extlink&oid=7880789&loc=d3e5710-111685

+ Details

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- Definition

The carrying amount of the consolidated Variable Interest Entity's liabilities included in the reporting entity's statement of financial position.

+ References

+ Details

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Variable Interest Entities and Other Investments - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Variable Interest Entity [Line Items]
Expenses related to consolidated VIEs	$ 133	$ 97	$ 333	$ 311
Impairment related to private capital investments			2
LIHC investments [Member]
Variable Interest Entity [Line Items]
Carrying amount of assets, consolidated VIEs	284		284
Carrying amount of liabilities, consolidated VIEs	9		9
Number of LIHC investment fund	2		2
Trusts owned and lease railcars [Member]
Variable Interest Entity [Line Items]
Carrying amount of assets, consolidated VIEs	61		61
Consolidated VIEs [Member]
Variable Interest Entity [Line Items]
Expenses related to consolidated VIEs	$ 11	$ 6	$ 26	$ 18