Leases (Details) $ in Thousands	3 Months Ended	6 Months Ended
	Jan. 31, 2020 USD ($)	Jan. 31, 2020 USD ($)
Leases [Abstract]
Operating lease cost	$ 712	$ 1,423
Short-term lease cost	75	133
Total lease cost	787	1,556
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ 685	$ 1,369
Weighted-average remaining lease term-operating leases	4 years 7 months 6 days	4 years 7 months 6 days
Weighted-average discount rate-operating leases	3.12%	3.12%