XML 81 R67.htm IDEA: XBRL DOCUMENT v3.7.0.1
Stockholders' Equity - Schedule of Weighted-Average Assumptions Used to Calculate Stock-Based Compensation for Stock Purchase under ESPP (Detail) - Employee stock purchase plan [Member]
12 Months Ended
Jan. 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
Volatility 44.00%
Expected term (in years) 6 months 29 days
Risk-free interest rate 0.10%
Dividend yield 0.00%