Loans Collectively Evaluated for Impairment (Detail) (Residential Loans, USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Residential Loans
Financing Receivable, Impaired [Line Items]
Principal balance	$ 1,993,690	$ 2,272,104
Recorded investment	2,013,694	2,295,471
Related allowance	$ 22,520	$ 27,891

The principal balance of financing receivables that were collectively evaluated for impairment.

No definition available.

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- Definition

The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

-Subparagraph (g)

-URI http://asc.fasb.org/extlink&oid=28368275&loc=SL6953423-111524

+ Details

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- Definition

The balance of financing receivables that were collectively evaluated for impairment.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

-Subparagraph (h)

-URI http://asc.fasb.org/extlink&oid=28368275&loc=SL6953423-111524

+ Details

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Balance Type:	debit
Period Type:	instant

- Details

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