Schedule of Available-for-sale Securities (Details) - USD ($) $ in Thousands		Oct. 31, 2022	Jul. 31, 2022
Debt Securities, Available-for-sale, Amortized Cost		$ 20,579	$ 22,849
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax			1
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax		(768)	(547)
Debt Securities, Available-for-sale		19,811	22,303
Certificates of Deposit [Member]
Debt Securities, Available-for-sale, Amortized Cost	[1]	2,000	2,000
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	[1]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	[1]	(3)	(14)
Debt Securities, Available-for-sale	[1]	1,997	1,986
US Treasury Bill Securities [Member]
Debt Securities, Available-for-sale, Amortized Cost		13,894	13,848
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax		(114)	(114)
Debt Securities, Available-for-sale		13,780	13,734
Corporate Bond Securities [Member]
Debt Securities, Available-for-sale, Amortized Cost		3,954	3,966
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax			1
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax		(650)	(416)
Debt Securities, Available-for-sale		3,304	3,551
Municipal Bonds [Member]
Debt Securities, Available-for-sale, Amortized Cost		731	3,035
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax		(1)	(3)
Debt Securities, Available-for-sale		$ 730	$ 3,032

[1] Each of the Company’s certificates of deposit has a CUSIP, was purchased in the secondary market through a broker and may be sold in the secondary market.