Intangible Assets - Fair Value of Residential MSRs (Detail)	9 Months Ended	12 Months Ended
Sep. 30, 2013	Dec. 31, 2012
Goodwill and Intangible Assets Disclosure [Abstract]
Annualized constant prepayment rate (CPR)	12.50%	22.40%
Constant discount rate	12.80%	11.30%
Weighted average life	4 years 11 months 16 days	3 years 4 months 24 days

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Discount rate used to estimate the fair value of servicing assets and servicing liabilities.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 50

-Section 50

-Paragraph 2

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=7882072&loc=d3e122596-111746

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- Definition

Estimated rate of prepayments of principal on servicing assets and servicing liabilities.

+ References

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- Definition

Weighted average life of financial assets and financial liabilities, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

+ Details

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