Leases (Lease Cost and Additional Information) (Details) - USD ($)	3 Months Ended
	Oct. 31, 2020	Oct. 31, 2019
Leases [Abstract]
Amortization of ROU assets	$ 12,000	$ 108,000
Interest on lease liabilities	1,000	2,000
Operating lease expense	2,488,000	2,637,000
Short-term lease expense	247,000	863,000
Variable lease expense	964,000	993,000
Sublease income	(17,000)	0
Total lease expense	3,695,000	4,603,000
Operating leases - Operating cash outflows	2,543,000	2,843,000
Finance leases - Operating cash outflows	1,000	2,000
Finance leases - Financing cash outflows	12,000	198,000
ROU assets obtained in the exchange for lease liabilities (non-cash): operating leases	$ 478,000	$ 598,000