Note 10 Employee Equity Incentive Plans (Share-based Compensation) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based Compensation Effect on Income before Taxes	$ 2,785	$ 3,451	$ 3,779
Benefit from Income Taxes	1,071	1,287	1,375
Net Stock-based Compensation Effects on Net Income	1,714	2,164	2,404
Cost of Good Sold [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based Compensation Effect on Income before Taxes	457	398	376
Research, Development and Engineering [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based Compensation Effect on Income before Taxes	978	1,030	917
Selling, General and Administrative [[Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based Compensation Effect on Income before Taxes	$ 1,350	$ 2,023	$ 2,486