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Stock-Based Compensation (Details) (USD $)	3 Months Ended		6 Months Ended
Stock-Based Compensation (Details) (USD $)	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Employee Stock Options [Member]
Schedule of Weighted-Average Assumptions Used to Estimate the Fair Value of Stock Options
Expected life (years)			4 years 6 months	3 years 9 months 18 days
Risk-free interest rate			0.70%	1.40%
Volatility			54.00%	48.00%
Dividend yield			0.00%	0.00%
Weighted average fair value			$ 2.47	$ 3.83
Employee Stock Purchase Plans [Member]
Schedule of Weighted-Average Assumptions Used to Estimate the Fair Value of Stock Options
Expected life (years)	6 months	6 months	6 months	6 months
Risk-free interest rate	0.20%	0.20%	0.20%	0.20%
Volatility	50.00%	55.00%	50.00%	55.00%
Dividend yield	0.00%	0.00%	0.00%	0.00%
Weighted average fair value	$ 1.50	$ 1.92	$ 1.50	$ 1.92

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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