Statement of Earnings (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Income Statement [Abstract]
Net revenues	$ 280,014	$ 368,004	$ 363,273
Cost of goods sold	195,134	248,760	241,526
Gross profit	84,880	119,244	121,747
Operating expenses:
Research, development and engineering	28,022	28,847	28,177
Selling, general and administrative	39,287	42,063	41,880
Amortization of acquisition-related intangible assets	2,244	2,524	6,937
Restructuring Charges	0	0	759
Impairment charges	0	6,448	702
Total operating expenses	69,553	79,882	78,455
Operating income	15,327	39,362	43,292
Other income (expense):
Interest income	334	367	285
Interest expense	(938)	(1,129)	(1,513)
Other income (expense), net	(41)	1,941	836
Income before Income Tax Provision	14,682	40,541	42,900
Provision for income tax	(7,034)	(10,235)	(6,253)
Net income	$ 7,648	$ 30,306	$ 36,647
Net income per share:
Basic	$ 0.25	$ 0.97	$ 1.17
Diluted	$ 0.24	$ 0.93	$ 1.14
Cash dividends per common share	$ 0.06	$ 0.00	$ 0.00
Weighted average shares used in per share calculation:
Basic	31,025	31,344	31,235
Diluted	31,695	32,496	32,008