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Stock-based Compensation - Summary of the grant-date fair value (Details) (USD $)	3 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Notes to Financial Statements
Grant-date fair value	$ 4.75
Volatility factor	77.01%
Dividend yield
Risk-free interest rate	1.74%
Expected term (in years)	7 years

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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