Note 11 Employee Equity Incentive Plans (Weighted Average Estimates and Assumptions) (Details) (USD $)	3 Months Ended
Jun. 30, 2012 Y	Jun. 30, 2011 Y
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award Fair Value Assumptions and Methodology [Line Items]
Weighted Average Estimated Fair Value of Grant Per Share	$ 5.47	$ 6.74
Risk-free Interest Rate	0.90%	1.90%
Expected Term in Years	6.34	5.95
Volatility	55.40%	55.70%
Dividend Yield	0.00%	0.00%
Employee Stock Purchase Plan 1999 [Member]
Share-based Compensation Arrangement by Share-based Payment Award Fair Value Assumptions and Methodology [Line Items]
Weighted Average Estimated Fair Value of Grant Per Share	$ 3.67	$ 2.51
Risk-free Interest Rate	0.10%	0.20%
Expected Term in Years	0.5	0.5
Volatility	46.80%	44.90%
Dividend Yield	0.00%	0.00%

The period of time an equity-based award is expected to be outstanding. An equity-based award's expected term is generally determined based on, among other factors, the instrument's contractual term and the effects of employees' expected exercise and post-vesting employment termination behavior.

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The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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