Leases - Summary of Supplemental Balance Sheet Information Related to Leases (Detail) $ in Thousands	Jul. 31, 2019 USD ($)
Finance Leases:
Property and equipment, at cost	$ 4,519
Accumulated depreciation	(473)
Property and equipment, net	$ 4,046
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:PropertyPlantAndEquipmentNet
Other accrued liabilities	$ 1,715
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:OtherAccruedLiabilitiesCurrent
Other liabilities	$ 2,366
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilitiesNoncurrent
Total finance lease liabilities	$ 4,081
Weighted average remaining lease terms:
Operating leases	6 years 2 months 12 days
Finance leases	2 years 9 months 18 days
Weighted average discount rate:
Operating leases	4.80%
Finance leases	4.10%