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		9 Months Ended
	Nov. 30, 2018	Nov. 30, 2017	Nov. 30, 2018	Nov. 30, 2017
Components of net periodic benefit cost
Service cost	$ 277	$ 271	$ 830	$ 812
Interest cost	568	567	1,705	1,702
Expected return on plan assets	(1,028)	(948)	(3,082)	(2,845)
Amortization of:
Unrecognized net loss	512	510	1,535	1,531
Net periodic benefit cost	$ 329	$ 400	$ 988	$ 1,200