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
	May 31, 2018	May 31, 2017
Components of net periodic benefit cost
Service cost	$ 277	$ 271
Interest cost	568	568
Expected return on plan assets	(1,027)	(949)
Amortization of:
Unrecognized net loss	511	510
Net periodic benefit cost	$ 329	$ 400