Stock and Stock Option Plans - Valuation Assumptions of Performance Based Nonvested Stock Awards (Detail) |
3 Months Ended |
|---|---|
|
Apr. 30, 2016
$ / shares
| |
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |
| Weighted-average expected volatility | 56.10% |
| Expected dividend yield | 0.00% |
| Weighted-average risk free rate | 0.60% |
| Performance Based Nonvested Stock Awards [Member] | |
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |
| Weighted-average fair value | $ 4.7 |
| Weighted-average expected volatility | 58.30% |
| Expected dividend yield | 0.00% |
| Weighted-average risk free rate | 0.90% |