Future Minimum Rental Payments under Capital and Operating Leases (Detail) $ in Thousands	Jul. 31, 2018 USD ($)
Leases [Abstract]
For the fiscal year ending July 31, 2019	$ 977
For the fiscal year ending July 31, 2020	974
For the fiscal year ending July 31, 2021	993
For the fiscal year ending July 31, 2022	1,015
For the fiscal year ending July 31, 2023	1,037
For the fiscal year ending July 31, 2024 and thereafter	4,098
Total minimum lease payments	9,094
Less amount representing interest	(2,999)
Present value of net minimum capital lease payments	6,095
Less current portion	(410)
Long-term capital lease obligations	5,685
For the fiscal year ending July 31, 2019	2,301
For the fiscal year ending July 31, 2020	1,544
For the fiscal year ending July 31, 2021	1,259
For the fiscal year ending July 31, 2022	1,046
For the fiscal year ending July 31, 2023	1,011
For the fiscal year ending July 31, 2024 and thereafter	6,723
Total minimum lease payments	$ 13,884