Pension Plan - Summary of Pension Expense Composed of Components Included in Cost of Goods Sold and Selling, General and Administrative Expenses (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Aug. 31, 2014	Aug. 31, 2013	Aug. 31, 2014	Aug. 31, 2013
Components of net periodic benefit cost
Service cost	$ 280	$ 316	$ 561	$ 631
Interest cost	612	600	1,224	1,201
Expected return on plan assets	(964)	(873)	(1,928)	(1,745)
Amortization of:
Prior service cost	(36)	(36)	(72)	(72)
Unrecognized net loss	381	513	762	1,025
Net periodic benefit cost	$ 273	$ 520	$ 547	$ 1,040