Consolidated Statements of Operations and Comprehensive Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Income Statement [Abstract]
Net sales	$ 322,431	$ 317,017	$ 313,044
Costs and expenses
Cost of sales	229,342	214,746	211,342
Selling, general and administrative expenses	83,375	76,047	75,062
Gain on bargain purchases	(19,990)	0	0
Interest expense (income), net	29	(112)	7
Other income, net	(12)	(305)	(8)
Costs and expenses	292,744	290,376	286,403
Income before income taxes	29,687	26,641	26,641
Income tax expense	1,183	9,405	9,687
Net income	$ 28,504	$ 17,236	$ 16,954
Net income per common share:
Basic (in dollars per share)	$ 3.14	$ 1.88	$ 1.82
Diluted (in dollars per share)	$ 3.13	$ 1.87	$ 1.80
Weighted average shares outstanding:
Basic (in shares)	9,074	9,147	9,326
Diluted (in shares)	9,115	9,239	9,410
Comprehensive income:
Net income	$ 28,504	$ 17,236	$ 16,954
Currency translation adjustment	45	0	0
Pension and postretirement benefits, net of tax	(46)	29	(72)
Comprehensive income	$ 28,503	$ 17,265	$ 16,882