Summary of Significant Accounting Policies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	9 Months Ended
Sep. 30, 2013	Sep. 30, 2012
Class of Stock [Line Items]
Highly liquid investments classified as cash equivalent, maturity period	3 months
Maximum period for loan classified as non-accrual loan	120 days
Minimum origination fee charged	1.11%	1.11%
Maximum origination fee charged	5.00%	5.00%
Net Credit risk exposure on fair value of Member loans	$ 0.4	$ 0.5
Vesting period	4 years
Computer Software, Intangible Asset
Class of Stock [Line Items]
Intangible assets, useful life	3 years
Minimum
Class of Stock [Line Items]
Property and equipment, estimated useful life	2 years
Maximum
Class of Stock [Line Items]
Property and equipment, estimated useful life	5 years

Highly Liquid Investments Maturity Period

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- Definition

Maximum origination fee charged.

+ References

No definition available.

+ Details

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- Definition

Maximum period for loan classified as nonaccrual loan.

+ References

No definition available.

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- Definition

Minimum origination fee charged.

+ References

No definition available.

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- Definition

Maximum amount of loss due to credit risk that, based on the gross fair value of the financial instrument, the entity would incur if parties to the financial instruments that make up the concentration failed completely to perform according to the terms of the contracts and the collateral or other security, if any, for the amount due proved to be of no value to the entity.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 21

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=28364263&loc=d3e13537-108611

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- Definition

Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

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- Definition

Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

+ References

No definition available.

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- Definition

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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