Consolidated Statements of Operations and Comprehensive Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Income Statement [Abstract]
Net sales	$ 317,017	$ 313,044	$ 320,459
Costs and expenses
Cost of sales	214,746	211,342	217,303
Selling, general and administrative expenses	76,047	75,062	75,204
Interest (income) expense, net	(112)	7	191
Other (income) expense, net	(305)	(8)	61
Total costs and expenses	290,376	286,403	292,759
Income from continuing operations before income taxes	26,641	26,641	27,700
Income tax expense	9,405	9,687	9,136
Income from continuing operations	17,236	16,954	18,564
Income from discontinued operations, net of tax	0	0	205
Net income	$ 17,236	$ 16,954	$ 18,769
Basic:
Continuing operations (in dollars per share)	$ 1.88	$ 1.82	$ 1.98
Discontinued operations (in dollars per share)	0.00	0.00	0.02
Total (in dollars per share)	1.88	1.82	2.00
Diluted:
Continuing operations (in dollars per share)	1.87	1.80	1.97
Discontinued operations (in dollars per share)	0.00	0.00	0.02
Total (in dollars per share)	$ 1.87	$ 1.80	$ 1.99
Weighted average shares outstanding:
Basic (in shares)	9,147	9,326	9,389
Diluted (in shares)	9,239	9,410	9,436
Comprehensive income:
Net income	$ 17,236	$ 16,954	$ 18,769
Postretirement medical plan, net of tax	29	(72)	21
Comprehensive income	$ 17,265	$ 16,882	$ 18,790