Income taxes Income tax narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015
Components of deferred income tax assets [Line Items]
Deferred tax liability on repatriation	$ 821	$ 1,530
Foreign Earnings Repatriated	$ 2,800
Deferred Tax Liability Not Recognized, Determination of Deferred Tax Liability is Not Practicable, Undistributed Earnings of Foreign Subsidiaries	Determination of the amount of unrecognized deferred income tax liabilities on these earnings is not practicable, because such liability, if any, is dependent on circumstances existing if and when remittance occurs.
Dividends, Cash	$ 2,000
Suspended excess tax (benefit) expense from stock options exercised	300
State NOL carryforward	1,419	1,291
Federal operating loss carryforward, gross	$ 11,500
Federal operating loss carryforward expires	Jan. 31, 2030
Operating Loss Carryforwards, expiration dates	expire at various times from 2016 to 2031
State NOL, subject to expiration	$ 1
Foreign tax credit	$ 2,861	2,088
Valuation Allowance, Methodologies and Assumptions	The Company continues to have a valuation allowance on its domestic DTAs since domestic losses continue to be generated.
Tax Credit Carryforward, Expiration Date	Jan. 31, 2022
Undistributed earnings of foreign subsidiaries	$ 40,400
Income Tax Examination, Description	No changes were made to the reported tax
Open Tax Year	2011
Open tax years up to the amount of research tax credit generated	January 31, 2002 through January 31, 2009
Denmark
Components of deferred income tax assets [Line Items]
Deferred tax liability on repatriation	$ 200
Foreign Earnings Repatriated	700
India
Components of deferred income tax assets [Line Items]
Deferred tax liability on repatriation	200	900
Foreign Earnings Repatriated		$ 4,200
Middle East [Member]
Components of deferred income tax assets [Line Items]
Foreign tax credit	$ 100