Annual report pursuant to Section 13 and 15(d)

Stockholders' Equity - Summary of Stock Unit Activity (Detail)

v3.8.0.1
Stockholders' Equity - Summary of Stock Unit Activity (Detail) - Restricted Stock Units Deferred Stock Units and Performance Stock Units [Member] - $ / shares
12 Months Ended
Jan. 31, 2018
Jan. 31, 2017
Jan. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Unvested Shares at beginning of period 1,453,058 1,053,045 435,306
Awarded Shares 796,304 837,927 904,344
Vested Shares (271,285) (208,474) (277,373)
Forfeited/expired/cancelled Shares (53,187) (229,440) (9,232)
Unvested Shares at end of period 1,924,890 1,453,058 1,053,045
Unvested Weighted average grant date fair value at beginning of period $ 5.54 $ 7.34 $ 8.91
Awarded Weighted average grant date fair value 3.07 3.07 6.46
Vested Weighted average grant date fair value 2.85 3.46 6.89
Forfeited/expired/cancelled Weighted average grant date fair value 5.71 6.68 8.42
Unvested Weighted average grant date fair value at end of period $ 4.89 $ 5.54 $ 7.34