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