Income taxes Reconcilation to the ETR rate (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Jan. 31, 2013	Jan. 31, 2012
Income Tax Expense [Line Items]
Tax benefit at federal statutory rate	$ (2,616)	$ (1,690)
Differences in foreign tax rate	842	1,429
Foreign tax credit	(67)	(1,300)
Research tax credit	(91)	(951)
Repatriation	0	1,810
Nontaxable income from the Canadian joint venture	(471)	(530)
State taxes, net of federal benefit	(216)	308
All other, net expense	266	330
Income Tax Expense (Benefit)	10,790	17
UNITED STATES
Income Tax Expense [Line Items]
valuation allowance	11,464	0
State and Local Jurisdiction [Member]
Income Tax Expense [Line Items]
valuation allowance	1,066	52
Foreign Tax Authority [Member]
Income Tax Expense [Line Items]
valuation allowance	$ 613	$ 559

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

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- Definition

The sum of the current income tax expense or benefit and the deferred income tax expense or benefit pertaining to continuing operations.

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-Publisher FASB

-Name Accounting Standards Codification

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-Glossary Income Tax Expense (or Benefit)

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The portion of the difference, between total income tax expense or benefit as reported in the Income Statement for the period and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations, that is attributable to total foreign income tax expense or benefit. The foreign income tax expense or benefit difference represents the income tax expense or benefit at applicable domestic statutory income tax rates applied to foreign earnings or loss for the period versus the foreign income tax expense or benefit calculated by applying the appropriate foreign tax rates.

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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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The portion of the difference, between total income tax expense or benefit as reported in the Income Statement for the year/accounting period and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations, that is attributable to all other items not otherwise listed in the existing taxonomy.

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The portion of the difference between total income tax expense or benefit as reported in the Income Statement and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations attributable to the repatriation of foreign earnings in the period.

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The portion of the difference between total income tax expense or benefit as reported in the Income Statement and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations attributable to foreign tax credits generated or utilized under enacted tax laws during the period.

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The portion of the difference between total income tax expense or benefit as reported in the Income Statement and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations attributable to research tax credits generated or utilized under enacted tax laws during the period.

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The amount of the change in the period in the valuation allowance for a specified deferred tax asset.

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