Note 5 - Restricted Cash - Restricted Cash (Details) - USD ($)	3 Months Ended	12 Months Ended
	Oct. 31, 2019	Jul. 31, 2018
Restricted cash, beginning of period	$ 1,821,392	$ 1,789,899
Interest received	7,529	31,493
Restricted cash, end of period	$ 1,828,921	$ 1,821,392