Leases (Lease Cost and Additional Information) (Details) - USD ($)	12 Months Ended
	Jul. 31, 2022	Jul. 31, 2021	Jul. 31, 2020
Leases [Abstract]
Amortization of ROU assets	$ 13,000	$ 36,000	$ 175,000
Interest on lease liabilities	1,000	3,000	4,000
Operating lease expense	11,658,000	12,152,000	10,728,000
Short-term lease expense	402,000	819,000	3,045,000
Variable lease expense	4,619,000	4,523,000	4,033,000
Sublease income	(67,000)	(67,000)	(22,000)
Total lease expense	16,626,000	17,466,000	17,963,000
Operating leases - Operating cash outflows	11,864,000	10,868,000	11,437,000
Finance leases - Operating cash outflows	1,000	3,000	4,000
Finance leases - Financing cash outflows	15,000	38,000	322,000
ROU assets obtained in the exchange for lease liabilities (non-cash): operating leases	$ 15,233,000	$ 24,987,000	$ 3,561,000