Recorded Investment in Residential Loans Collectively Evaluated for Impairment Past Due (Detail) (Collectively Evaluated for Impairment, USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Collectively Evaluated for Impairment
30-59 Days Past Due	$ 54,843	$ 65,708
60-89 Days Past Due	20,826	21,674
90+ Days Past Due	131,991	133,695
Current	3,701,189	3,623,295
Recorded investment	$ 3,908,849	$ 3,844,372

The amount of the recorded investment in a contractual right to receive money on demand or on fixed or determinable dates that is recognized as an asset in the creditor's statement of financial position. Examples include, but are not limited to, accounts receivable (with terms exceeding one year), notes receivable and receivables relating to lessor's rights to payments from leases other than operating leases that have been recorded as assets.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Financing Receivable
-URI http://asc.fasb.org/extlink&oid=6953735

+ Details

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Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- 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=6965416&loc=SL6953401-111524

+ Details

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Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

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

+ References

+ Details

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Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Financing receivables that are current.

+ References

+ Details

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Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

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

+ References

+ Details

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Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant