Expected Amortization Expenses (Detail) (USD $) In Thousands, unless otherwise specified	Apr. 30, 2014	Apr. 30, 2013
Acquired Finite Lived Intangible Assets
Schedule Of Estimated Future Amortization Expense [Line Items]
2015	$ 263
2016	118
2017	118
2018	29
Finite-Lived Intangible Assets, Net, Total	528	617
Capitalized Software
Schedule Of Estimated Future Amortization Expense [Line Items]
2015	3,588
2016	3,588
2017	3,288
Finite-Lived Intangible Assets, Net, Total	$ 10,464