Lease information Future minimum payments (Details) (USD $) In Thousands, unless otherwise specified	Jan. 31, 2014	Jan. 31, 2013
Operating Leased Assets [Line Items]
Operating Leases, Future Minimum Payments Due, Next Twelve Months	$ 2,211
Capital Lease Obligations, Current	705
Operating Leases, Future Minimum Payments, Due in Two Years	1,567
Capital Leases, Future Minimum Payments Due in Two Years	724
Operating Leases, Future Minimum Payments, Due in Three Years	1,378
Capital Leases, Future Minimum Payments Due in Three Years	678
Operating Leases, Future Minimum Payments, Due in Four Years	1,274
Capital Leases, Future Minimum Payments Due in Four Years	157
Operating Leases, Future Minimum Payments, Due in Five Years	1,243
Capital Leases, Future Minimum Payments Due in Five Years	24
Operating Leases, Future Minimum Payments, Due Thereafter	1,526
Capital Leases, Future Minimum Payments Due Thereafter	0
Operating Leases, Future Minimum Payments Due	9,199
Capital leases, future minimum payments, interest included in payments	2,288
Interest Portion of Minimum Lease Payments, Sale Leaseback Transactions	221
Capital Lease Obligations	$ 2,067	$ 2,584