Annual report pursuant to Section 13 and 15(d)

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

v3.10.0.1
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, 2018
Apr. 30, 2018
Jan. 31, 2018
Oct. 31, 2017
Jul. 31, 2017
Apr. 30, 2017
Jan. 31, 2017
Oct. 31, 2016
Jul. 31, 2018
Jul. 31, 2017
Jul. 31, 2016
Computation of basic and diluted net loss per share [Abstract]                      
Net (loss) income (in Dollars) $ (5,764) $ (3,016) $ (901) $ (640) $ 94 $ (71) $ (1,053) $ (1,474) $ (10,321) $ (2,504) $ 45,286
Weighted-average common shares outstanding - basic                 46,972 46,350 46,153
Add: effect of dilutive stock options and restricted stock                     449
Weighted-average common shares outstanding - diluted                 46,972 46,350 46,602
Net (loss) income per share – basic (in Dollars per share)                 $ (0.22) $ (0.05) $ 0.98
Net (loss) income per share – diluted (in Dollars per share)                 $ (0.22) $ (0.05) $ 0.97