Annual report pursuant to Section 13 and 15(d)

Summary of significant accounting policies (Details) - Computation of basic and diluted net loss per share

v3.7.0.1
Summary of significant accounting policies (Details) - Computation of basic and diluted net loss per share - USD ($)
$ / shares in Units, shares in Thousands, $ 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, 2017
Jul. 31, 2016
Jul. 31, 2015
Computation of basic and diluted net loss per share [Abstract]                      
Net (loss) income (in Dollars) $ 94 $ (71) $ (1,053) $ (1,474) $ 36,135 $ (2,115) $ 6,832 $ 4,434 $ (2,504) $ 45,286 $ (2,285)
Weighted-average common shares outstanding - basic                 46,350 46,153 45,355
Add: effect of dilutive stock options and restricted stock                   449  
Weighted-average common shares outstanding - diluted                 46,350 46,602 45,355
Net (loss) income per share – basic (in Dollars per share) $ 0.00 $ 0.00 $ (0.02) $ (0.03) $ 0.78 $ (0.05) $ 0.15 $ 0.10 $ (0.05) $ 0.98 $ (0.05)
Net (loss) income per share – diluted (in Dollars per share) $ 0.00 $ 0.00 $ (0.02) $ (0.03) $ 0.77 $ (0.05) $ 0.15 $ 0.10 $ (0.05) $ 0.97 $ (0.05)