Stock-Based Compensation (Details) (USD $)	3 Months Ended	12 Months Ended
	Apr. 30, 2013	Jan. 31, 2013
Summary of activity under Option and Stock Plans
Beginning Balance Outstanding, Shares	926,224
Beginning Balance Outstanding, Weighted Average Exercise Price	$ 14.34
Beginning Balance Outstanding, Weighted Average Remaining Contract Term	5 years 7 months 17 days	5 years 4 months 21 days
Beginning Balance, Weighted Average Fair Value, Outstanding	$ 5.93
Granted, Shares	71,000
Granted, Weighted Average Exercise Price	$ 16.11
Forfeited, Shares
Forfeited, Weighted Average Exercise Price
Exercise of stock options, Shares
Exercised, Weighted Average Exercise Price
Ending Balance Outstanding, Shares	997,224	926,224
Ending Balance Outstanding, Weighted Average Exercise Price	$ 14.47	$ 14.34
Ending Balance Outstanding, Weighted Average Remaining Contract Term	5 years 7 months 17 days	5 years 4 months 21 days
Ending Balance, Weighted Average Fair Value, Outstanding	$ 5.74	$ 5.93
Exercisable, Shares	700,724	537,724
Exercisable, Weighted Average Exercise Price	$ 13.17	$ 12.16
Exercisable, Weighted Average Remaining Contract Term	4 years 9 months 11 days	4 years 5 months 16 days
Exercisable, Weighted Average Fair Value	$ 5.94	$ 6.12