Note 12 - Stock-based Compensation - Schedule of Outstanding Unvested Stock Options (Details)	3 Months Ended
	Oct. 31, 2023 $ / shares shares
Nonvested balance (in shares) | shares	1,803,265
Nonvested, Weighted Average Grant-Date Fair Value (in dollars per share) | $ / shares	$ 2.28
Granted, number of stock options (in shares) | shares	17,500
Granted, Weighted Average Grant-Date Fair Value (in dollars per share) | $ / shares	$ 3.36
Cancelled/Forfeited (in shares) | shares	(12,300)
Cancelled/Forfeited, Weighted Average Grant-Date Fair Value (in dollars per share) | $ / shares	$ 2.37
Vested (in shares) | shares	(133,062)
Vested, Weighted Average Grant-Date Fair Value (in dollars per share) | $ / shares	$ 2.18
Nonvested balance (in shares) | shares	1,675,403
Nonvested, Weighted Average Grant-Date Fair Value (in dollars per share) | $ / shares	$ 2.29