Income taxes Reconcilation to the ETR rate (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Jan. 31, 2015	Jan. 31, 2014
Income Tax Expense [Line Items]
Tax benefit at federal statutory rate	$ 1,130	$ 4,182
Differences in foreign tax rate	455	(3,049)
Foreign tax credit	(793)	0
Research tax credit	(29)	0
Repatriation	847	0
Nontaxable income from the Canadian joint venture	(666)	(179)
State taxes, net of federal benefit	(62)	(192)
All other, net expense	447	(46)
Income tax expense (benefit)	3,241us-gaap_IncomeTaxExpenseBenefit	(493)us-gaap_IncomeTaxExpenseBenefit
United States
Income Tax Expense [Line Items]
Valuation allowance	1,778	0
State and Local Jurisdiction [Member]
Income Tax Expense [Line Items]
Valuation allowance	119	0
Foreign Tax Authority [Member]
Income Tax Expense [Line Items]
Valuation allowance	$ 15	$ (1,209)

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Nontaxable income from the Canadian joint venture - Tax expense reverse income for the year

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to foreign income tax expense (benefit).

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The amount of income tax expense or benefit for the period computed by applying the domestic federal statutory tax rates to pretax income from continuing operations.

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Amount of increase (decrease) in the valuation allowance for a specified deferred tax asset.

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