Condensed Consolidated Statements of Income Unaudited - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2017	Oct. 31, 2016
Income Statement [Abstract]
Net sales	$ 68,794	$ 67,795	$ 164,665	$ 149,976
Costs of goods sold	44,327	43,484	105,088	93,864
Gross profit	24,467	24,311	59,577	56,112
Selling, general and administrative expenses	19,798	17,780	49,768	44,915
Gain on sale of property, plant & equipment	(15)	(1)	(16)	(2)
Operating income	4,684	6,532	9,825	11,199
Interest expense, net	456	326	1,280	1,076
Income (loss) before income taxes	4,228	6,206	8,545	10,123
Income tax (benefit) expense	1,704	(17,792)	3,204	(17,622)
Net income (loss)	$ 2,524	$ 23,998	$ 5,341	$ 27,745
Net income (loss) per common share:
Basic (usd per share)	$ 0.16	$ 1.59	$ 0.35	$ 1.84
Diluted (usd per share)	$ 0.16	$ 1.57	$ 0.35	$ 1.83
Weighted average shares outstanding:
Basic (shares)	15,317	15,128	15,220	15,047
Diluted (shares)	15,483	15,293	15,324	15,186