Cash Flow Information (Schedule of supplemental disclosure) (Details) - USD ($)	3 Months Ended
	Oct. 31, 2019	Oct. 31, 2018
Cash Flow Information
Interest paid, net of capitalized interest of $26,456 (2019) and $15,067 (2018)	$ 22,861	$ 34,272
Income taxes paid
Non-cash information
Initial recognition of operating lease right-of-use assets	27,104,937
Initial recognition of operating lease liabilities	$ 17,863,507