Note 9 - Long-term Debt (Details Textual)			3 Months Ended		6 Months Ended
	Dec. 05, 2018 USD ($) shares	Feb. 09, 2016	Jan. 31, 2019 USD ($)	Jan. 31, 2018 USD ($)	Jan. 31, 2019 USD ($) shares	Jan. 31, 2018 USD ($)	Jul. 31, 2018 USD ($)
Long-term Debt, Gross	$ 20,000,000		$ 20,000,000		$ 20,000,000		$ 20,000,000
Stock Issued Value Issued For Extension Fees					$ 1,400,000
Stock Issued, Shares Issued For Extension Fees | shares					1,180,328
Amortization of Debt Discount (Premium)			$ 358,349	$ 308,409	$ 666,120	$ 605,831
Credit Agreement [Member]
Long-term Debt, Gross	$ 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 | 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	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
Debt Instrument, Maturity Date	Jan. 31, 2022	Jan. 01, 2020