Retirement plans Plan assets (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jan. 31, 2014 Rate	Jan. 31, 2013 Rate	Jan. 31, 2012
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Actual Plan Asset Allocations	100.00%
US Government Agencies Securities, at Carrying Value	$ 0
Defined Benefit Plan, Fair Value of Plan Assets	6,351	6,065	5,502
Defined Benefit Plan, Target Allocation Percentage	target asset allocations of 55% equities (with a range of 40% - 65%),  25% fixed income (with a range of 20% - 35%) and 20% Alternative Investments (with a range of 15% - 25%)
Defined Benefit Plan, Actual Return on Plan Assets	531	574
Net periodic benefit cost, expected long-term return on assets	0.00%	8.00%
Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Investment Owned, Percent of Net Assets	50.00%
Available-for-sale Securities, Equity Securities	3,340	3,343
Bonds [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Investment Owned, Percent of Net Assets	37.00%
Available-for-sale Securities	2,453	2,183
US Treasury and Government [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
US Government Agencies Securities, at Carrying Value		279
Real Estate Funds [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Investment Owned, Percent of Net Assets	2.00%
Available-for-sale Securities	149	126
Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Available-for-sale Securities	5,942	5,931
Money Market Funds [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Available-for-sale Securities	$ 409	$ 134
Money Market Funds [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Investment Owned, Percent of Net Assets	11.00%