Capital Stock - Components of Redeemable Convertible Preference Shares (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	Jan. 31, 2012
Redeemable Convertible Preference Shares [Member]
Convertible Preference Shares [Line Items]
Preference shares, shares authorized	14,526,660
Preference shares, shares outstanding	13,315,727
Initial Liquidation Preference	$ 51,235
Series A Redeemable convertible preference shares [Member]
Convertible Preference Shares [Line Items]
Preference shares, par value	$ 0.00045
Preference shares, shares authorized	5,611,111
Preference shares, shares outstanding	5,611,107
Initial Liquidation Preference	10,100
Series A Redeemable convertible preference shares [Member] \| Redeemable Convertible Preference Shares [Member]
Convertible Preference Shares [Line Items]
Preference shares, par value	$ 0.00045
Preference shares, shares authorized	5,611,111
Preference shares, shares outstanding	5,611,107
Initial Liquidation Preference	10,100
Series B Redeemable convertible preference shares [Member]
Convertible Preference Shares [Line Items]
Preference shares, par value	$ 0.00045
Preference shares, shares authorized	3,665,550
Preference shares, shares outstanding	3,629,253
Initial Liquidation Preference	13,000
Series B Redeemable convertible preference shares [Member] \| Redeemable Convertible Preference Shares [Member]
Convertible Preference Shares [Line Items]
Preference shares, par value	$ 0.00045
Preference shares, shares authorized	3,665,550
Preference shares, shares outstanding	3,629,253
Initial Liquidation Preference	13,000
Series C Redeemable convertible preference shares [Member]
Convertible Preference Shares [Line Items]
Preference shares, par value	$ 0.00045
Preference shares, shares authorized	3,027,777
Preference shares, shares outstanding	3,027,771
Initial Liquidation Preference	16,350
Series C Redeemable convertible preference shares [Member] \| Redeemable Convertible Preference Shares [Member]
Convertible Preference Shares [Line Items]
Preference shares, par value	$ 0.00045
Preference shares, shares authorized	3,027,777
Preference shares, shares outstanding	3,027,771
Initial Liquidation Preference	16,350
Series D Redeemable convertible preference shares [Member]
Convertible Preference Shares [Line Items]
Preference shares, par value	$ 0.00045
Preference shares, shares authorized	2,222,222
Preference shares, shares outstanding	1,047,596
Initial Liquidation Preference	11,785
Series D Redeemable convertible preference shares [Member] \| Redeemable Convertible Preference Shares [Member]
Convertible Preference Shares [Line Items]
Preference shares, par value	$ 0.00045
Preference shares, shares authorized	2,222,222
Preference shares, shares outstanding	1,047,596
Initial Liquidation Preference	$ 11,785

Face amount or stated value per share of stock classified as temporary equity; generally not indicative of the fair market value per 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.

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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.

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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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