Discontinued Operations Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2017	Jan. 31, 2016
Gross sales price		$ 22,000
Net proceeds from sale of discontinued operations		18,400
Funds held in escrow related to the sale of Filtration assets	$ 502	1,905
Sales price of Bolingbrook building	7,100
Net proceeds from sale of Bolingbrook building	1,900
Gross proceeds from sale of other property	500
Proceeds from Sale of Real Estate	400
Gross price from sale of productive assets	1,500
Net proceeds from sale of buildings	1,400
Discontinued operation, income tax expense	1,043	94
Income (loss) from discontinued operations, net of tax	688	(6,044)
Impairment expense on discontinued operations	$ 0	$ 6,480