Share-Based Compensation - Stock Options (Details) |
3 Months Ended |
|---|---|
Apr. 30, 2016 | |
| Vesting Details [Line Items] | |
| Contractual term | 5 years 11 months 28 days |
| Stock Options [Member] | |
| Vesting Details [Line Items] | |
| Award vesting percentage | 25.00% |
| Award vesting period | 4 years |
| Requisite service period for retirement eligibility | 10 years |
| Minimum age of individual for retirement eligibility | 55 years |
| Contractual term | 10 years |