Recorded Investment and Past Due Status of Residential Loans Collectively Evaluated for Impairment (Detail) (Residential Loans, USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	$ 1,479,667	$ 1,779,161
Collectively Evaluated for Impairment
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	28,484	34,187
60-89 Days Past Due	8,464	13,248
90+ Days Past Due	69,223	79,010
Current	$ 1,373,496	$ 1,652,716

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

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=35738203&loc=SL6953423-111524

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- Definition

Financing receivables that are less than 60 days past due but more than 29 days past due.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 7A

-URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953401-111524

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- Definition

Financing receivables that are less than 90 days past due but more than 59 days past due.

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- Definition

Financing receivables that are current.

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- Definition

Financing receivables that are equal to or greater than 90 days past due.

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