Schedule of Available-for-sale Securities, Unrealized Loss Position (Details) - USD ($) $ in Thousands	Apr. 30, 2024	Jul. 31, 2023
Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss	$ 568	$ 645
Debt Securities, Available-for-Sale, Unrealized Loss Position	29,384	41,635
US Treasury Bill Securities [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss	131	148
Debt Securities, Available-for-Sale, Unrealized Loss Position	23,579	31,038
US Government-sponsored Enterprises Debt Securities [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss	6	8
Debt Securities, Available-for-Sale, Unrealized Loss Position	2,372	3,873
Corporate Bond Securities [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss	431	485
Debt Securities, Available-for-Sale, Unrealized Loss Position	$ 3,433	3,368
Certificates of Deposit [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss		4
Debt Securities, Available-for-Sale, Unrealized Loss Position		$ 3,356