Servicing Assets and Residual Interests Economic Assumptions (Detail)	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Fixed Rate Residential Mortgage
Assumption For Fair Value As Of Balance Sheet Date Of Interests Continued To Be Held By Transferor Servicing Assets Or Liabilities [Line Items]
Weighted- Average Life (in years)	6 years 2 months 12 days	6 years 8 months 12 days
Prepayment Speed (annual)	12.60%	10.80%
Discount Rate (annual)		10.00%
OAS spread (bps)	900
Adjustable Rate Residential Mortgage
Assumption For Fair Value As Of Balance Sheet Date Of Interests Continued To Be Held By Transferor Servicing Assets Or Liabilities [Line Items]
Weighted- Average Life (in years)	3 years 7 months 6 days	3 years 8 months 12 days
Prepayment Speed (annual)	23.40%	22.50%
Discount Rate (annual)		11.70%
OAS spread (bps)	1,180

The OAS represents the spread that is added to the discount rate so that the sum of the discounted cash flows equals the market price; therefore, it is a measure of the extra yield over the reference discount factor that the Corporation expects to earn by holding the asset.

No definition available.

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- Definition

Weighted average life of securitized assets regardless of when the transfer occurred, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 20

-Section 50

-Paragraph 4

-Subparagraph (b)(2)

-URI http://asc.fasb.org/extlink&oid=13989330&loc=d3e107314-111719

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- Definition

Discount rate which is used to value residual cash flows generated by financial assets of a securitization, asset-backed financing arrangement, or similar transfer regardless of when the transfer occurred.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 20

-Section 50

-Paragraph 4

-Subparagraph (b)(1)

-URI http://asc.fasb.org/extlink&oid=13989330&loc=d3e107314-111719

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- Definition

Estimated rate of prepayment of principal on financial assets regardless of when the transfer occurred.

+ References

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