Pension Plan - Additional Information (Detail) - USD ($) |
3 Months Ended | 12 Months Ended | |
|---|---|---|---|
May 31, 2016 |
Feb. 28, 2017 |
Feb. 29, 2016 |
|
| Defined Benefit Plan Disclosure [Line Items] | |||
| Employees covered under noncontributory Pension Plan | 21.00% | ||
| Compensation period preceding retirement and termination | 5 years | ||
| Contributions | $ 3,000,000 | ||
| Period used for calculating Pension Plan liability | 25 years | ||
| Scenario Forecast [Member] | |||
| Defined Benefit Plan Disclosure [Line Items] | |||
| Minimum required contribution to the plan is approximately | $ 0 | ||
| Minimum [Member] | Scenario Forecast [Member] | |||
| Defined Benefit Plan Disclosure [Line Items] | |||
| Contributions | 2,000,000 | ||
| Maximum [Member] | Scenario Forecast [Member] | |||
| Defined Benefit Plan Disclosure [Line Items] | |||
| Contributions | $ 3,000,000 | ||