Significant accounting policies Long lived assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015
Property, Plant and Equipment [Line Items]
Depreciation and amortization	$ 4,204	$ 4,187
Land, buildings and improvements	14,758	13,704
Machinery and equipment	41,534	38,509
Furniture, office equipment and computer systems	5,632	5,945
Transportation equipment	40	43
Subtotal	61,964	58,201
Less accumulated depreciation and amortization	36,564	34,036
Property, plant and equipment, net of accumulated depreciation	$ 25,400	$ 24,165