v2.4.0.8
Income taxes (Details) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 9 Months Ended
Oct. 31, 2014
Oct. 31, 2013
Oct. 31, 2014
Oct. 31, 2013
Jan. 31, 2014
Income Tax Disclosure [Abstract]          
Income tax provision $ 1,100 $ 1,280 $ 5,047 $ 3,724  
Effective tax rate 26.50% 39.30% 36.50% 38.50%  
Net impact of discrete tax items on effective tax rate 12.10%   3.10%    
Unrecognized tax benefits 229   229   256
Net unrecognized tax benefits 53   53   47
Anticipated decrease in total gross unrecognized tax benefits within 12 months $ 6   $ 6