Leases - Lease Cost and Additional Information (Details) - USD ($)	3 Months Ended	6 Months Ended
	Jan. 31, 2020	Jan. 31, 2020
Leases [Abstract]
Amortization of ROU assets	$ 44,000	$ 152,000
Interest on lease liabilities	1,000	3,000
Operating lease expense	2,699,000	5,336,000
Short-term lease expense	878,000	1,741,000
Variable lease expense	1,016,000	2,009,000
Sublease income	0	0
Total lease expense	$ 4,638,000	9,241,000
Operating leases - Operating cash outflows		5,725,000
Finance leases - Operating cash outflows		3,000
Finance leases - Financing cash outflows		300,000
ROU assets obtained in the exchange for lease liabilities - operating leases		$ 1,823,000