Note 12 - Stock-based Compensation - Summary of Outstanding Unvested RSUs (Details) - Restricted Stock Units (RSUs) [Member] $ / shares in Units, $ in Thousands	3 Months Ended
	Oct. 31, 2023 USD ($) $ / shares shares
Number of Restricted Stock Units (in shares) | shares	979,500
Grant Date Fair Value (in dollars per share) | $ / shares	$ 3.32
Remaining Life (Year)	2 years 2 months 23 days
Aggregate Intrinsic Value | $	$ 5,827
July 21, 2021 [Member]
Number of Restricted Stock Units (in shares) | shares	135,875
Grant Date Fair Value (in dollars per share) | $ / shares	$ 2.15
Remaining Life (Year)	8 months 19 days
Aggregate Intrinsic Value | $	$ 808
May 01, 2022 [Member]
Number of Restricted Stock Units (in shares) | shares	39,216
Grant Date Fair Value (in dollars per share) | $ / shares	$ 4.25
Remaining Life (Year)	1 year 6 months
Aggregate Intrinsic Value | $	$ 233
July 29, 2022 [Member]
Number of Restricted Stock Units (in shares) | shares	184,023
Grant Date Fair Value (in dollars per share) | $ / shares	$ 3.98
Remaining Life (Year)	1 year 9 months
Aggregate Intrinsic Value | $	$ 1,095
July 31, 2023 [Member]
Number of Restricted Stock Units (in shares) | shares	620,386
Grant Date Fair Value (in dollars per share) | $ / shares	$ 3.32
Remaining Life (Year)	2 years 9 months
Aggregate Intrinsic Value | $	$ 3,691