Future Minimum Rental Payments under Capital and Operating Leases (Detail) $ in Thousands	Jul. 31, 2017 USD ($)
Income Tax Disclosure [Abstract]
For the fiscal year ending July 31, 2018	$ 948
For the fiscal year ending July 31, 2019	938
For the fiscal year ending July 31, 2020	933
For the fiscal year ending July 31, 2021	951
For the fiscal year ending July 31, 2022	973
For the fiscal year ending July 31, 2023 and thereafter	5,015
Total minimum lease payments	9,758
Less amount representing interest	(3,285)
Present value of net minimum capital lease payments	6,473
Present value of net minimum capital lease payments	6,473
Less current portion	(378)
Long-term capital lease obligations	6,095
For the fiscal year ending July 31, 2018	2,547
For the fiscal year ending July 31, 2019	2,152
For the fiscal year ending July 31, 2020	1,434
For the fiscal year ending July 31, 2021	1,123
For the fiscal year ending July 31, 2022	907
For the fiscal year ending July 31, 2023 and thereafter	7,493
Total minimum lease payments	$ 15,656