Stock-Based Compensation (Details) (USD $)	9 Months Ended	12 Months Ended
	Oct. 31, 2012	Jan. 31, 2012
Summary of activity under Option and Stock Plans
Outstanding, January 31, 2012, Shares	817,000
Outstanding, January 31, 2012, Weighted Average Exercise Price	$ 12.10
Outstanding, January 31, 2012, Weighted Average Remaining Contract Term	5 years 29 days	4 years 11 months 9 days
Outstanding, January 31, 2012, Weighted Average Fair Value, Outstanding	$ 5.68
Granted, Shares	173,000
Granted, Weighted Average Exercise Price	$ 16.32
Forfeited, Shares	(30,000)
Forfeited, Weighted Average Exercise Price	$ 8.66
Exercised, Shares	(121,000)
Exercised, Weighted Average Exercise Price	$ 8.75
Outstanding, October 31, 2012, Shares	839,000	817,000
Outstanding, October 31, 2012, Weighted Average Exercise Price	$ 13.58	$ 12.10
Outstanding, October 31, 2012, Weighted Average Remaining Contract Term	5 years 29 days	4 years 11 months 9 days
Outstanding, October 31, 2012, Weighted Average Fair Value	$ 5.86	$ 5.68
Exercisable, October 31, 2012, Shares	546,000	605,000
Exercisable, October 31, 2012, Weighted Average Exercise Price	$ 11.88	$ 11.47
Exercisable, October 31, 2012, Weighted Average Remaining Contract Term	4 years 7 months 24 days	4 years 10 months 21 days
Exercisable, October 31, 2012, Weighted Average Fair Value	$ 6.05	$ 5.89
Exercisable, January 31, 2012, Shares	605,000
Exercisable, January 31, 2012, Weighted Average Exercise Price	$ 11.47
Exercisable, January 31, 2012, Weighted Average Remaining Contract Term	4 years 7 months 24 days	4 years 10 months 21 days
Exercisable, January 31, 2012, Weighted Average Fair Value	$ 5.89