STOCK-BASED COMPENSATION - Summary of Assumptions Used to Estimate Fair Value of Stock Options Granted (Details) |
3 Months Ended | |
|---|---|---|
Apr. 30, 2017 |
Apr. 30, 2016 |
|
| Share-based Compensation Arrangement by Share-based Payment Award | ||
| Expected life (in years) | 3 years 4 months 6 days | 5 years 6 months |
| Stock Options Plans | ||
| Share-based Compensation Arrangement by Share-based Payment Award | ||
| Dividend yield | 1.09% | 2.07% |
| Expected volatility | 35.96% | 34.08% |
| Risk-free interest rate | 1.59% | 1.02% |
| Expected life (in years) | 3 years 4 months 6 days | 5 years 6 months |