Types of Loan and Lease Modifications (Detail)	3 Months Ended	9 Months Ended
Sep. 30, 2013 Contract	Sep. 30, 2013 Contract
Financing Receivable, Modifications [Line Items]
Interest-Rate Change	1	2
Loan Term Extension
Interest Rate Change and Term Extension		1
Interest-Only Period	1	3
Contractual Payment Reduction (Leases only)	2	4
Forgiveness of Interest		1
Residential mortgage
Financing Receivable, Modifications [Line Items]
Loan Term Extension
Interest Rate Change and Term Extension		1
Forgiveness of Interest		1
Home equity lines and loans
Financing Receivable, Modifications [Line Items]
Interest-Rate Change		1
Loan Term Extension
Interest-Only Period		1
Commercial and industrial
Financing Receivable, Modifications [Line Items]
Loan Term Extension
Interest-Only Period	1	2
Leases
Financing Receivable, Modifications [Line Items]
Loan Term Extension
Contractual Payment Reduction (Leases only)	2	4
Consumer
Financing Receivable, Modifications [Line Items]
Interest-Rate Change	1	1
Loan Term Extension

Financing Receivables Number Of Contracts Contractual Payment Reduction

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Financing Receivables Number Of Contracts, Forgiveness of Interest

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Financing Receivables Number Of Contracts Interest Rate Change

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Financing Receivables Number Of Contracts Interest Rate Change And Term Extension

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Financing Receivables Number Of Contracts Interest Rate Change With Interest Only Period

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Financing Receivables Number Of Contracts Loan Term Extension

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