Income taxes Reconcilation to the ETR rate (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jan. 31, 2014	Jan. 31, 2013
Income Tax Expense [Line Items]
Tax benefit at federal statutory rate	$ 4,182	$ (3,037)
Differences in foreign tax rate	(3,049)	823
Foreign tax credit	0	(67)
Research tax credit	0	(46)
Nontaxable income from the Canadian joint venture	(179)	(471)
State taxes, net of federal benefit	(192)	(247)
All other, net expense	(46)	310
Income tax (benefit) expense	(493)	11,825
United States
Income Tax Expense [Line Items]
Valuation allowance	0	12,975
State and Local Jurisdiction [Member]
Income Tax Expense [Line Items]
Valuation allowance	0	972
Foreign Tax Authority [Member]
Income Tax Expense [Line Items]
Valuation allowance	$ (1,209)	$ 613