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		9 Months Ended
	Nov. 30, 2013	Nov. 30, 2012	Nov. 30, 2013	Nov. 30, 2012
Components of net periodic benefit cost
Service cost	$ 315	$ 322	$ 946	$ 963
Interest cost	601	600	1,802	1,801
Expected return on plan assets	(872)	(802)	(2,617)	(2,406)
Amortization of:
Prior service cost	(37)	(37)	(109)	(109)
Unrecognized net loss	514	456	1,539	1,368
Net periodic benefit cost	$ 521	$ 539	$ 1,561	$ 1,617