v3.7.0.1
Net Loss Per Share - Summary of Diluted Net Loss Per Common Share (Detail) - shares
shares in Thousands
3 Months Ended
Apr. 30, 2017
Apr. 30, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Total anti-dilutive securities (in shares) 38,678 40,385
Outstanding common stock options    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Total anti-dilutive securities (in shares) 8,468 11,843
Shares subject to repurchase    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Total anti-dilutive securities (in shares) 70 492
Unvested restricted stock awards, units, and PRSUs    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Total anti-dilutive securities (in shares) 15,133 13,214
Shares related to the convertible senior notes    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Total anti-dilutive securities (in shares) 7,261 7,261
Shares subject to warrants related to the issuance of convertible senior notes    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Total anti-dilutive securities (in shares) 7,261 7,261
Shares issuable pursuant to the ESPP    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Total anti-dilutive securities (in shares) 485 314