Note 9 - Long-term Debt (Details Textual)		12 Months Ended
	Dec. 05, 2018 USD ($) shares	Jul. 31, 2020 USD ($) shares	Jul. 31, 2019 USD ($)	Jul. 31, 2018 USD ($) shares
Long-term Debt, Gross		$ 20,000,000	$ 20,000,000
Stock Issued During Period, Shares, Credit Facility (in shares) | shares		1,743,462		641,574
Stock Issued During Period, Value, Credit Facility		$ 1,400,000	1,400,000	$ 900,000
Percentage of Outstanding Principal of Anniversary Fee		7.00%		4.50%
Amortization of Debt Discount (Premium)		$ 1,669,514	$ 1,464,989	$ 1,180,139
Credit Agreement [Member]
Long-term Debt, Gross	$ 20,000,000	$ 20,000,000		$ 20,000,000
Third Extension Fees Percentage	7.00%
Stock Issued Value Issued For Extension Fees	$ 1,400,000
Stock Issued, Shares Issued For Extension Fees (in shares) | shares	1,180,328
Rate Of Anniversary Fee Payable In Next Twelve Months	7.00%
Rate Of Anniversary Fee Payable In Second Year	6.50%
Rate Of Anniversary Fee Payable in Third Year	6.00%
Percentage of Discount on Volume Weighted Average Price	10.00%
Anniversary Fee, Payment in Shares, Trading Days for Weighted Average Share Price	5
Debt Instrument, Term (Year)	8 years 182 days
Debt Instrument, Interest Rate, Stated Percentage	8.00%
Debt Instrument, Interest Rate, Effective Percentage	16.67%
Anniversary Fees Payable In Next Twelve Months	$ 1,400,000
Anniversary Fees Payable In Second Year	1,300,000
Anniversary Fees Payable In Third Year	$ 1,200,000