Additional Information about Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended
Sep. 30, 2013
Assets and Liabilities At Fair Value On Recurring Basis [Line Items]
Member Loans at fair value, Fair value at December 31, 2012	$ 781,215
Member Loans at fair value, Issuances	1,366,207
Member Loans at fair value, Principal repayments	(341,256)
Member Loans at fair value, Loans sold to third parties	(250,433)
Recoveries from sale and collection of charged-off loans	(1,180)
Member Loans at fair value, Carrying value before fair value adjustments	1,554,553
Member Loans at fair value, Fair valuation adjustments, included in earnings	(37,877)
Member Loans at fair value, Fair value at September 30, 2013	1,516,676
Notes and Certificates, Fair value at December 31, 2012	785,316
Notes and Certificates,Issuances	1,115,694
Notes and Certificates, Principal repayments	(339,048)
Notes and Certificates, Loans sold to third parties
Recoveries from sale and collection of charged-off loans	(1,139)
Notes and Certificates, Carrying value before fair value adjustments	1,560,823
Notes and Certificates, Fair valuation adjustments, included in earnings	(37,848)
Notes and Certificates, Fair value at September 30, 2013	$ 1,522,975

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Fair value assets measured on recurring basis loss included in investment income.

+ References

No definition available.

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- Definition

Fair value measurement with unobservable inputs reconciliation recurring basis liability gain included in earnings.

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No definition available.

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- Definition

Principal amount of member loan before fair value adjustment.

+ References

No definition available.

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- Definition

Principal amount of notes before fair value adjustment.

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No definition available.

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- Definition

Recoveries from Sale and Collection of Charged Off Loans for Member Loans

+ References

No definition available.

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- Definition

Recoveries from Sale and Collection of Charged Off Loans for Notes and Certificates

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No definition available.

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- Definition

Amount of issuances of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)

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Amount of sale of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of settlement of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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

-Publisher FASB

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-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=25499696&loc=d3e19207-110258

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Amount of issuances of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of sales of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of settlements of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=25499696&loc=d3e19207-110258

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