Fair Value of Stock Options Under Black Scholes Option Pricing Model Based on Closing Stock Price on Date of Grant (Detail) (Stock option, USD $)	3 Months Ended
Oct. 31, 2013	Jul. 31, 2013	Apr. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price	$ 0.47	$ 0.004	$ 0.41
Expected term (in years)	6 years	3 years	4 years 7 months 2 days
Volatility	67.20%	29.70%	26.00%
Dividend rate	0.00%	0.00%	0.00%
Interest rate	1.40%	0.60%	0.50%
Mr. Mark Meyers
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)		3 years	3 years
Volatility		29.70%	17.40%
Dividend rate		0.00%	0.00%
Interest rate		0.50%	0.82%

Agreed upon price for the exchange of the underlying asset.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (e)

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

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Expected dividends to be paid to holders of the underlying shares or financial instruments (expressed as a percentage of the share or instrument's price).

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Period the instrument, asset or liability is expected to be outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Measure of dispersion, in percentage terms (for instance, the standard deviation or variance), for a given stock price.

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Risk-free interest rate assumption used in valuing an instrument.

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