Credit Quality and the Allowance for Loan and Lease Losses - Additional Information (Detail) (USD $) In Millions	3 Months Ended	6 Months Ended
Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Financing Receivable, Impaired [Line Items]
Interest income recognized on impaired loans	$ 55	$ 67	$ 103	$ 111
Average impaired loans	2,980	3,300	2,963	3,200
Lower Limit
Financing Receivable, Impaired [Line Items]
Larger commercial loans, subject to impairment review	$ 1		$ 1

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

The average recorded investment related to impaired financing receivables.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=6965416&loc=d3e5212-111524
-Subparagraph (c)(1)

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=6965416&loc=d3e5258-111524

+ Details

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- Definition

The interest income recognized during the time within that period that the financing receivables were impaired.

+ References

+ Details

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- Definition

The recorded investment related to impaired financing receivables.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 14A
-URI http://asc.fasb.org/extlink&oid=6965416&loc=SL6953550-111524
-Subparagraph (b)

+ Details

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Period Type:	instant