Stock-Based Compensation - Information on stock options outstanding (Details) - USD ($)	9 Months Ended
	Apr. 30, 2018	Jul. 31, 2017
Options Outstanding	13,365	18,095
Weighted Average Exercise Price per Share	$ 41.64	$ 31.02
Options Weighted Average Remaining Life (Years)	6 months 7 days
Options Aggregate Intrinsic Value	$ 24,404
Exercise Price 1
Options Range of Exercise Price	$ 1.00
Options Range of Exercise Price	$ 1.00
Options Outstanding	12,515
Weighted Average Exercise Price per Share	$ 1.00
Options Weighted Average Remaining Life (Years)	5 months 5 days
Options Aggregate Intrinsic Value	$ 24,404
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)	1 year 10 months 10 days
Options Aggregate Intrinsic Value