Information on stock options outstanding - Stock-Based Compensation (Details 2) - USD ($)	6 Months Ended
	Jan. 31, 2018	Jul. 31, 2017
Options Outstanding	18,095	18,095
Weighted Average Exercise Price per Share	$ 31.02	$ 31.02
Options Weighted Average Remaining Life (Years)	7 months
Options Aggregate Intrinsic Value	$ 47,424
Exercise Price 1
Options Range of Exercise Price	$ 1.00
Options Range of Exercise Price	$ 1.00
Options Outstanding	17,245
Weighted Average Exercise Price per Share	$ 1.00
Options Weighted Average Remaining Life (Years)	6 months
Exercise Price 640
Options Range of Exercise Price	$ 640.00
Options Range of Exercise Price	$ 640.00
Options Outstanding	850
Weighted Average Exercise Price per Share	$ 640.00
Options Weighted Average Remaining Life (Years)	2 years 1 month