Estimated Annual Amortization Expense (Detail) (USD $) In Thousands, unless otherwise specified	Apr. 30, 2014
Expected Amortization Expense [Line Items]
Estimated annual amortization expense, For the fiscal year ending July 31, 2014	$ 12,267
Estimated annual amortization expense, For the fiscal year ending July 31, 2015	12,102
Estimated annual amortization expense, For the fiscal year ending July 31, 2016	10,760
Estimated annual amortization expense, For the fiscal year ending July 31, 2017	10,134
Estimated annual amortization expense, For the fiscal year ending July 31, 2018	9,687
Estimated annual amortization expense, For the fiscal year ending July 31, 2019	9,021
Estimated annual amortization expense, For the fiscal year ending July 31, 2020 and thereafter	49,163
Estimated annual amortization expense, Total	$ 113,134