Income Taxes (Details 1) - USD ($) $ in Thousands	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2014
Deferred income tax assets (liabilities):
Net operating loss carryforward	$ 74,292	$ 57,098
Accrued expenses	3,808	338
Stock based compensation	(4,043)	(464)
Valuation allowance	(74,057)	(56,972)	$ (53,681)	$ (50,191)
TOTAL NET DEFERRED INCOME TAX ASSETS (LIABILITIES)