Estimated Amortization Expense (Detail) $ in Thousands	Apr. 30, 2018 USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Estimated annual amortization expense, For the fiscal year ending July 31, 2018	$ 55,118
Estimated annual amortization expense, For the fiscal year ending July 31, 2019	50,043
Estimated annual amortization expense, For the fiscal year ending July 31, 2020	46,194
Estimated annual amortization expense, For the fiscal year ending July 31, 2021	42,860
Estimated annual amortization expense, For the fiscal year ending July 31, 2022	37,753
Estimated annual amortization expense, For the fiscal year ending July 31, 2023 and thereafter	211,498
Estimated annual amortization expense, Total	$ 443,466