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, 2013	Aug. 31, 2012	Aug. 31, 2013	Aug. 31, 2012
Components of net periodic benefit cost
Service cost	$ 316	$ 320	$ 631	$ 641
Interest cost	600	601	1,201	1,201
Expected return on plan assets	(873)	(802)	(1,745)	(1,604)
Amortization of:
Prior service cost	(36)	(36)	(72)	(72)
Unrecognized net loss	513	456	1,025	912
Net periodic benefit cost	$ 520	$ 539	$ 1,040	$ 1,078