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Stock Options and Stock-Based Compensation (Details)	12 Months Ended
Stock Options and Stock-Based Compensation (Details)	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Fair value of options granted
Dividend yield	0.00%	0.00%	0.00%
Maximum [Member]
Fair value of options granted
Expected volatility	47.00%	47.00%	47.00%
Risk free interest rate	0.80%	1.90%	2.20%
Weighted average option life	4 years 6 months	5 years	5 years
Minimum [Member]
Fair value of options granted
Expected volatility		46.00%	46.00%
Risk free interest rate	0.60%	0.70%	1.50%
Weighted average option life		4 years 7 months 6 days	4 years 9 months 18 days

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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