Statement of Earnings (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Income Statement [Abstract]
Net revenues	$ 336,330	$ 280,014	$ 368,004
Cost of goods sold	236,120	195,134	248,760
Gross profit	100,210	84,880	119,244
Operating expenses:
Research, development and engineering	30,884	28,022	28,847
Selling, general and administrative	41,983	39,287	42,063
Amortization of acquisition-related intangible assets	10,521	2,244	2,524
Impairment charges	0	0	6,448
Total operating expenses	83,388	69,553	79,882
Operating income	16,822	15,327	39,362
Other income (expense):
Interest income	157	334	367
Interest expense	(1,579)	(938)	(1,129)
Other income (expense), net	(1,941)	(41)	1,941
Income before income tax provision	13,459	14,682	40,541
Provision for income tax	(7,413)	(7,034)	(10,235)
Net income (loss)	$ 6,046	$ 7,648	$ 30,306
Net income per share:
Basic	$ 0.19	$ 0.25	$ 0.97
Diluted	$ 0.19	$ 0.24	$ 0.93
Cash dividends per common share	$ 0.12	$ 0.06	$ 0.00
Weighted average shares used in per share calculation:
Basic	31,146	31,025	31,344
Diluted	31,916	31,695	32,496