Note 12 Employee Equity Incentive Plans (Tables)

6 Months Ended

Sep. 30, 2013

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block]

		Three Months Ended September 30,				Six Months Ended September 30,
Statement of Operations Classifications			2013		2012		2013		2012
		(unaudited)				(unaudited)
Cost of goods sold		$	83	$	113	$	249	$	230
Research, development and engineering			248		283		456		564
Selling, general and administrative expenses			339		640		636		1,337
Stock-based compensation effect in income before taxes			670		1,036		1,341		2,131
Provision for income taxes (1)			208		363		416		746
Net stock-based compensation effects in net income		$	462	$	673	$	925	$	1,385
________________
(1)	Estimated at an income tax rate of 31% in fiscal year 2014 and 35% in fiscal year 2013.

Schedule of Employee Service Share-based Compensation, Fair Value Assumptions and Methodology [Table Text Block]

		Stock Options								Purchase Plan (1)
		Three Months Ended September 30,				Six Months Ended September 30,				Six Months Ended September 30,
			2013		2012		2013		2012		2013		2012
Weighted average estimated fair
	value of grant per share	$	4.95	$	5.01	$	4.95	$	5.21	$	2.60	$	3.67
Risk-free interest rate			1.9%		1.0%		1.9%		1.0%		0.1%		0.1%
Expected term in years			6.07		6.34		6.07		6.34		0.5		0.5
Volatility			55.5%		55.5%		55.5%		55.4%		38.5%		46.8%
Dividend yield			0%		0%		0%		0%		0%		0%
(1)	Under the stock purchase plan, rights to purchase shares are only granted during the first and third quarters of each fiscal year.

Schedule of Share-based Compensation, Stock Options Activity [Table Text Block]

			Weighted Average
		Number of	Exercise Price			Intrinsic Value (1)
		Shares	Per Share
						(000)
Balance at March 31, 2013		5,327,473	$	10.04
	Options granted	239,000	$	9.27
	Options exercised	(226,050)	$	7.69	$	836
	Options cancelled	(19,000)	$	10.77
	Options expired	(2,500)	$	12.13
Balance at September 30, 2013		5,318,923	$	10.10
Exercisable at September 30, 2013		4,114,423	$	9.93
Exercisable at March 31, 2013		4,065,473	$	9.74
(1)	Represents the difference between the exercise price and the value of our common stock at the time of exercise.