Stock-based compensation (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	9 Months Ended	12 Months Ended
	Oct. 31, 2013	Jan. 31, 2013
Stock Option [Member]
Option activity [Line Items]
Outstanding at beginning of year		969
Weighted Average Exercise Price Per Share		$ 10.77
Weighted Average Remaining Contractual Term		6 years 7 months 24 days
Options Outstanding Aggregate Intrinsic Value	$ 2,770	$ 40
Granted	102
Granted Weighted average exercise price	$ 10.50
Exercised	(135)
Exercised Weighted Average Exercise Price Per Share	$ 6.72
Exercised Aggregate Intrinsic Value	506
Expired or forfeited	(55)
Expired or Forfeited Weighted Average Exercise Price Per Share	$ 12.64
Outstanding end of period	881
Outstanding Weighted Average Exercise Price Per Share	$ 11.25
Outstanding Weighted Average Remaining Contractual Term	6 years 3 months 24 days
Exercisable end of period	602
Exercisable Weighted Average Remaining Contractual Term	5 years 1 month 24 days
Exercisable Weighted Average Exercise Price Per Share	$ 12.67
Exercisable Aggregate Intrinsic Value	1,748
unvested option [Member]
Option activity [Line Items]
Outstanding at beginning of year	279	383
Weighted Average Exercise Price Per Share	$ 8.18	$ 6.91
Options Outstanding Aggregate Intrinsic Value	$ 1,022	$ 4
Vested	(181)
Expired or forfeited	(25)
Expired or Forfeited Weighted Average Exercise Price Per Share	$ 6.96