Recent Accounting Pronouncements (Details) - USD ($)	3 Months Ended		9 Months Ended
	Apr. 30, 2017	Apr. 30, 2016	Apr. 30, 2017	Apr. 30, 2016
Recent Accounting Pronouncements
Reduction of income tax expense		$ 797,000		$ 2,071,000
ASU 2016-09 Share-Based Payment Accounting | New Accounting Pronouncement, Early Adoption, Effect
Recent Accounting Pronouncements
Reduction of income tax expense	$ (95,000)		$ 2,191,000