v3.7.0.1
Common Stock and Stockholders' Equity - PRSU's (Detail) - All Other Employees - Performance Based Restricted Stock Unit PRSU - USD ($)
shares in Millions, $ in Millions
3 Months Ended 12 Months Ended
Apr. 30, 2017
Jan. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
RSUs granted, number of Shares   0.3
Compensation related cost $ 6