Pension Plan - Company's Target Asset Allocation Percentage, by Asset Class (Detail)	12 Months Ended
	Feb. 28, 2017
Minimum [Member] | Cash [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Percentage	1.00%
Minimum [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Percentage	35.00%
Minimum [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Percentage	45.00%
Maximum [Member] | Cash [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Percentage	5.00%
Maximum [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Percentage	55.00%
Maximum [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Percentage	60.00%