Redeemable Convertible Preferred Stock - Schedule of Preferred Stock (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2013
Temporary Equity [Line Items]
Preferred Shares Authorized	88,894,772us-gaap_TemporaryEquitySharesAuthorized
Preferred Shares Issued	85,207,356us-gaap_TemporaryEquitySharesIssued
Preferred Shares Outstanding	85,207,356
Redemption Value /Liquidation Preference	$ 81,990
Carrying Value	81,525
Seed Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Preferred Shares Authorized	2,500,000
Issuance Date	2006-12
Preferred Shares Issued	2,500,000
Preferred Shares Outstanding	2,500,000
Redemption Value /Liquidation Preference	2,000
Carrying Value	2,000
Series A Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Preferred Shares Authorized	9,307,692
Issuance Date	2007-05
Preferred Shares Issued	9,307,692
Preferred Shares Outstanding	9,307,692
Redemption Value /Liquidation Preference	12,100
Carrying Value	12,100
Series B Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Preferred Shares Authorized	4,077,500
Issuance Date	2007-12
Preferred Shares Issued	3,562,500
Preferred Shares Outstanding	3,562,500
Redemption Value /Liquidation Preference	7,125
Carrying Value	7,125
Series B-1 Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Preferred Shares Authorized	5,000,000
Issuance Date	2009-07
Preferred Shares Issued	4,842,500
Preferred Shares Outstanding	4,842,500
Redemption Value /Liquidation Preference	9,685
Carrying Value	9,685
Series C Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Preferred Shares Authorized	33,310,787
Issuance Date	November 2010 and June 2011
Preferred Shares Issued	31,836,392
Preferred Shares Outstanding	31,836,392
Redemption Value /Liquidation Preference	23,559
Carrying Value	23,094
Series D Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Preferred Shares Authorized	34,698,793
Issuance Date	December 2011 and November 2012
Preferred Shares Issued	33,158,272
Preferred Shares Outstanding	33,158,272
Redemption Value /Liquidation Preference	27,521
Carrying Value	$ 27,521

Redeemable convertible preferred stock issuance date year and month.

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- Definition

Redeemable convertible preferred stock issuance period.

+ References

No definition available.

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- Definition

The aggregate liquidation preference (or restrictions) of stock classified as temporary equity that has a preference in involuntary liquidation considerably in excess of the par or stated value of the shares. The liquidation preference is the difference between the preference in liquidation and the par or stated values of the share. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. If convertible, the issuer does not control the actions or events necessary to issue the maximum number of shares that could be required to be delivered under the conversion option if the holder exercises the option to convert the stock to another class of equity. If the security is a warrant or a rights issue, the warrant or rights issue is considered to be temporary equity if the issuer cannot demonstrate that it would be able to deliver upon the exercise of the option by the holder in all cases. Includes stock with put option held by ESOP and stock redeemable by holder only in the event of a change in control of the issuer.

+ References

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- Definition

The maximum number of securities classified as temporary equity that are permitted to be issued by an entity's charter and bylaws. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. If convertible, the issuer does not control the actions or events necessary to issue the maximum number of shares that could be required to be delivered under the conversion option if the holder exercises the option to convert the stock to another class of equity. If the security is a warrant or a rights issue, the warrant or rights issue is considered to be temporary equity if the issuer cannot demonstrate that it would be able to deliver upon the exercise of the option by the holder in all cases. Includes stock with put option held by ESOP and stock redeemable by holder only in the event of a change in control of the issuer.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.27(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 28

-Subparagraph b

-Article 5

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- Definition

The number of securities classified as temporary equity that have been sold (or granted) to the entity's shareholders. Securities issued include securities outstanding and securities held in treasury. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. If convertible, the issuer does not control the actions or events necessary to issue the maximum number of shares that could be required to be delivered under the conversion option if the holder exercises the option to convert the stock to another class of equity. If the security is a warrant or a rights issue, the warrant or rights issue is considered to be temporary equity if the issuer cannot demonstrate that it would be able to deliver upon the exercise of the option by the holder in all cases. Includes stock with put option held by ESOP and stock redeemable by holder only in the event of a change in control of the issuer.

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- Definition

The number of securities classified as temporary equity that have been issued and are held by the entity's shareholders. Securities outstanding equals securities issued minus securities held in treasury. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. If convertible, the issuer does not control the actions or events necessary to issue the maximum number of shares that could be required to be delivered under the conversion option if the holder exercises the option to convert the stock to another class of equity. If the security is a warrant or a rights issue, the warrant or rights issue is considered to be temporary equity if the issuer cannot demonstrate that it would be able to deliver upon the exercise of the option by the holder in all cases. Includes stock with put option held by ESOP and stock redeemable by holder only in the event of a change in control of the issuer.

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- Definition

Carrying amount of the par value of temporary equity outstanding. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. Includes stock with put option held by ESOP and stock redeemable by holder only in the event of a change in control of the issuer.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph d

-Article 4

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 28

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (27)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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