Consolidated Statements of Operations and Comprehensive Income (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013
Income Statement [Abstract]
Net sales	$ 313,044	$ 320,459	$ 364,193
Costs and expenses
Cost of sales	211,342	217,303	255,102
Selling, general and administrative expenses	75,062	75,204	80,619
Disposition of product line, net	0	0	5,798
Interest expense (income), net	7	191	(51)
Other (income) expense, net	(8)	61	88
Total costs and expenses	286,403	292,759	341,556
Income from continuing operations before income taxes	26,641	27,700	22,637
Income tax expense	9,687	9,136	7,049
Income from continuing operations	16,954	18,564	15,588
Income (loss) from discontinued operations, net of tax	0	205	(361)
Net income	16,954	18,769	15,227
Basic:
Continuing operations (in dollars per share)	$ 1.82	$ 1.98	$ 1.63
Discontinued operations (in dollars per share)	$ 0.00	$ 0.02	$ (0.04)
Total (in dollars per share)	$ 1.82	$ 2.00	$ 1.59
Diluted:
Continuing operations (in dollars per share)	$ 1.80	$ 1.97	$ 1.63
Discontinued operations (in dollars per share)	$ 0.00	$ 0.02	$ (0.04)
Total (in dollars per share)	$ 1.80	$ 1.99	$ 1.59
Weighted average shares outstanding:
Basic (in shares)	9,326	9,389	9,562
Diluted (in shares)	9,410	9,436	9,568
Comprehensive income:
Net income	16,954	18,769	15,227
Postretirement medical plan, net of tax	(72)	21	(15)
Comprehensive income	$ 16,882	$ 18,790	$ 15,212