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Stock Option Plans (Details)	12 Months Ended
Stock Option Plans (Details)	Jan. 31, 2013	Jan. 31, 2012	Jan. 31, 2011
Schedule of fair value option award
Expected dividend yield	0.00%	0.00%	0.00%
Minimum [Member]
Schedule of fair value option award
Risk free interest rate	0.58%	1.52%	1.82%
Expected life	3 years 3 months 11 days	2 years 10 months 6 days	2 years 4 months 24 days
Expected volatility	59.00%	54.00%	57.00%
Maximum [Member]
Schedule of fair value option award
Risk free interest rate	0.78%	2.00%	1.97%
Expected life	6 years 7 months 6 days	4 years 10 months 21 days	4 years 4 months 24 days
Expected volatility	60.00%	55.00%	58.00%

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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