Income Taxes (Details 7) - USD ($)	12 Months Ended
	Jul. 31, 2015	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2012
Income Taxes
Repatriated dividends	$ 0	$ 0
Cumulative amount of undistributed earnings indefinitely reinvested outside the United States	$ 16,900,000
Reconciliation of the beginning and ending amounts of gross unrecognized tax benefits
Activity during period		$ (124,000)
Unrecognized tax benefits at the end of the period			$ 124,000	$ 124,000