Leases (Lease Cost and Additional Information) (Details) - USD ($)	3 Months Ended
	Oct. 31, 2021	Oct. 31, 2020
Leases [Abstract]
Amortization of ROU assets	$ 4,000	$ 12,000
Interest on lease liabilities	0	1,000
Operating lease expense	2,924,000	2,488,000
Short-term lease expense	94,000	247,000
Variable lease expense	1,176,000	964,000
Sublease income	(17,000)	(17,000)
Total lease expense	4,181,000	3,695,000
Operating leases - Operating cash outflows	2,828,000	2,543,000
Finance leases - Operating cash outflows	0	1,000
Finance leases - Financing cash outflows	6,000	12,000
ROU assets obtained in the exchange for lease liabilities (non-cash): operating leases	$ 6,667,000	$ 478,000