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	3 Months Ended		6 Months Ended
	Aug. 31, 2017	Aug. 31, 2016	Aug. 31, 2017	Aug. 31, 2016
Components of net periodic benefit cost
Service cost	$ 270	$ 292	$ 541	$ 583
Interest cost	567	593	1,135	1,186
Expected return on plan assets	(948)	(916)	(1,897)	(1,832)
Amortization of:
Unrecognized net loss	511	670	1,021	1,341
Net periodic benefit cost	$ 400	$ 639	$ 800	$ 1,278