Note 11 Employee Equity Incentive Plans (Allocated Share-based Compensation Expense) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 30, 2014		Jun. 30, 2013
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based Compensation Effect in Income before Taxes	$ 681		$ 671
Provision for Income Taxes	211	[1]	208	[1]
Net Stock-based Compensation Effects on Net Income	470		463
Estimated Statutory Income Tax Rate	31.00%		31.00%
Cost of Goods Sold [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based Compensation Effect in Income before Taxes	108		166
Research, Development and Engineering [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based Compensation Effect in Income before Taxes	189		208
Selling, General and Administrative Expenses [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based Compensation Effect in Income before Taxes	$ 384		$ 297

[1]  Estimated at a statutory income tax rate of 31% in fiscal year 2015 and 2014, respectively.