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, 2014	Nov. 30, 2013	Nov. 30, 2014	Nov. 30, 2013
Components of net periodic benefit cost
Service cost	$ 281	$ 315	$ 842	$ 946
Interest cost	611	601	1,835	1,802
Expected return on plan assets	(964)	(872)	(2,892)	(2,617)
Amortization of:
Prior service cost	(36)	(37)	(108)	(109)
Unrecognized net loss	381	514	1,143	1,539
Net periodic benefit cost	$ 273	$ 521	$ 820	$ 1,561