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.

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 210.5-02.28(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Preferred Stock and Stockholders' Equity (Deficit) - Summary of Authorized, Issued and Outstanding Shares of Preferred Stock by Series (Detail) - USD ($) $ in Thousands	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Temporary Equity [Line Items]
Shares Authorized		147,964,577
Shares Outstanding		139,278,610
Liquidation Preference		$ 119,622
Redemption Amount		$ 57,086
Preferred Stock [Member]
Temporary Equity [Line Items]
Shares Authorized	10,000,000
Series A-1 Redeemable Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Shares Authorized	0	135,826,497
Shares Outstanding	0	127,140,530	116,424,125
Liquidation Preference	$ 0	$ 114,172
Redemption Amount		$ 57,086
Junior Preferred Stock [Member]
Temporary Equity [Line Items]
Shares Authorized		12,138,080
Shares Outstanding		12,138,080
Liquidation Preference		$ 5,450