Annual report pursuant to Section 13 and 15(d)

Net Income (Loss) Per Share - Schedule of Earnings Per Share, Basic and Diluted (Detail)

v3.8.0.1
Net Income (Loss) Per Share - Schedule of Earnings Per Share, Basic and Diluted (Detail) - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
3 Months Ended 12 Months Ended
Jan. 31, 2018
Oct. 31, 2017
Jul. 31, 2017
Apr. 30, 2017
Jan. 31, 2017
Oct. 31, 2016
Jul. 31, 2016
Apr. 30, 2016
Jan. 31, 2018
Jan. 31, 2017
Jan. 31, 2016
Earnings Per Share Basic And Diluted [Line Items]                      
Net income (loss) $ 20,618 $ (220) $ (1,529) $ (5,371) $ (27,376) $ (8,082) $ (26,884) $ (8,907) $ 13,498 $ (71,249) $ (47,697)
Weighted average shares used in computing net income (loss) per share - basic                 35,412 34,970 33,506
Effect of dilutive shares:                      
Dilutive potential common shares                 273    
Weighted average shares used in computing net income (loss) per share - diluted                 35,685 34,970 33,506
Net income (loss) per share:                      
Basic $ 0.58 $ 0.00 $ (0.05) $ (0.15) $ (0.78) $ (0.23) $ (0.77) $ (0.26) $ 0.38 $ (2.04) $ (1.42)
Diluted $ 0.58 $ 0.00 $ (0.05) $ (0.15) $ (0.78) $ (0.23) $ (0.77) $ (0.26) $ 0.38 $ (2.04) $ (1.42)
Stock Options [Member]                      
Effect of dilutive shares:                      
Dilutive potential common shares                 60    
Restricted Stock Units [Member]                      
Effect of dilutive shares:                      
Dilutive potential common shares                 63    
Deferred Stock Units [Member]                      
Effect of dilutive shares:                      
Dilutive potential common shares                 84    
Performance Stock Units (PSUs) [Member]                      
Effect of dilutive shares:                      
Dilutive potential common shares                 66