Leases - Lease Cost and Additional Information (Details) - USD ($)	3 Months Ended	9 Months Ended
	Apr. 30, 2020	Apr. 30, 2020
Leases [Abstract]
Amortization of ROU assets	$ 0	$ 152,000
Interest on lease liabilities	0	3,000
Operating lease expense	2,733,000	8,069,000
Short-term lease expense	798,000	2,539,000
Variable lease expense	1,004,000	3,013,000
Sublease income	(5,000)	(5,000)
Total lease expense	$ 4,530,000	13,771,000
Operating leases - Operating cash outflows		8,681,000
Finance leases - Operating cash outflows		3,000
Finance leases - Financing cash outflows		300,000
ROU assets obtained in the exchange for lease liabilities (non-cash): operating leases		$ 3,096,000