Recent Accounting Pronouncements (Details) - USD ($)	3 Months Ended
	Oct. 31, 2016	Oct. 31, 2015
Recent Accounting Pronouncements
Reduction of income tax expense		$ 613,000
ASU 2016-09 Share-Based Payment Accounting | New Accounting Pronouncement, Early Adoption, Effect
Recent Accounting Pronouncements
Reduction of income tax expense	$ 2,241,000