Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Consolidated Statements of Operations [Abstract]
Sales	$ 133,485	$ 139,725	$ 194,552	$ 194,294
Costs and expenses
Cost of sales	92,654	99,663	136,523	140,096
Selling, general and administrative expenses	22,854	23,528	41,424	43,087
Disposition of product line, net	5,798	0	5,798	0
Interest (income) expense, net	(14)	111	(67)	154
Other (income) expense, net	(66)	119	(52)	137
Total costs and expenses	121,226	123,421	183,626	183,474
Income from continuing operations before income taxes	12,259	16,304	10,926	10,820
Income tax expense	5,419	5,990	4,953	3,953
Income from continuing operations	6,840	10,314	5,973	6,867
Income from discontinued operations, net of tax	81	5,171	44	1,049
Net income	$ 6,921	$ 15,485	$ 6,017	$ 7,916
Basic:
Continuing operations	$ 0.71	$ 1.06	$ 0.62	$ 0.71
Discontinued operations	$ 0.01	$ 0.53	$ 0.00	$ 0.11
Total	$ 0.72	$ 1.59	$ 0.63	$ 0.81
Diluted:
Continuing operations	$ 0.71	$ 1.06	$ 0.62	$ 0.70
Discontinued operations	$ 0.01	$ 0.53	$ 0.00	$ 0.11
Total	$ 0.72	$ 1.59	$ 0.63	$ 0.81
Weighted average shares outstanding
Basic	9,592	9,741	9,617	9,738
Diluted	9,621	9,747	9,620	9,743
Cash dividends per share of common stock	$ 0.15	$ 0.15	$ 0.30	$ 0.30