Annual report pursuant to Section 13 and 15(d)

Net Income (Loss) Per Share - Schedule of Anti-dilutive Securities Excluded from Computation of Earnings Per Share (Detail)

v3.8.0.1
Net Income (Loss) Per Share - Schedule of Anti-dilutive Securities Excluded from Computation of Earnings Per Share (Detail) - shares
shares in Thousands
 12 Months Ended
Jan. 31, 2018
Jan. 31, 2017
Jan. 31, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Anti-dilutive potentially outstanding common shares 1,991 2,251 1,674
Stock Options [Member]      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Anti-dilutive potentially outstanding common shares 1,522 1,415 1,493
Restricted Stock Units [Member]      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Anti-dilutive potentially outstanding common shares 159 448 145
Deferred Stock Units [Member]      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Anti-dilutive potentially outstanding common shares 13 70 31
Performance Stock Units (PSUs) [Member]      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Anti-dilutive potentially outstanding common shares 297 318 5