Annual report pursuant to Section 13 and 15(d)

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

v3.5.0.2
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, 2016
Apr. 30, 2016
Jan. 31, 2016
Oct. 31, 2015
Jul. 31, 2015
Apr. 30, 2015
Jan. 31, 2015
Oct. 31, 2014
Jul. 31, 2016
Jul. 31, 2015
Jul. 31, 2014
Computation of basic and diluted net loss per share [Abstract]                      
Net income (loss) (in Dollars) $ 36,135 $ (2,115) $ 6,832 $ 4,434 $ 8,442 $ (2,907) $ (4,091) $ (3,729) $ 45,286 $ (2,285) $ (9,977)
Weighted-average common shares outstanding - basic                 46,153 45,355 42,561
Add: effect of dilutive stock options and restricted stock                 449    
Weighted-average common shares outstanding - diluted                 46,602 45,355 42,561
Net income (loss) per share – basic (in Dollars per share) $ 0.78 $ (0.05) $ 0.15 $ 0.10         $ 0.98 $ (0.05) $ (0.23)
Net income (loss) per share – diluted (in Dollars per share) $ 0.77 $ (0.05) $ 0.15 $ 0.10         $ 0.97 $ (0.05) $ (0.23)