Income Taxes (Details 2) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Jul. 31, 2017	Apr. 30, 2017	Jan. 31, 2017	Oct. 31, 2016	Jul. 31, 2016	Apr. 30, 2016	Jan. 31, 2016	Oct. 31, 2015	Jul. 31, 2015	Apr. 30, 2015	Jan. 31, 2015	Oct. 31, 2014	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2015
Schedule of differences between income taxes expected at the federal statutory income tax rate and income taxes provided
Federal income tax at statutory rate													$ 15,524	$ 2,939	$ (262)
Permanent differences													(759)	(2)	1,048
Valuation allowance													(17,085)	(3,394)	(3,500)
Other													15	(3)
State and local income tax, net of federal benefit													2,292	464
PROVISION FOR (INCOME TAXES) INCOME TAX BENEFITS	$ 3	$ 3	$ 0	$ 7	$ 15	$ (25)	$ 0	$ 6	$ 2,660	$ (801)	$ 100	$ 755	$ 13	$ (4)	$ 2,714