Quarterly Results (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended																12 Months Ended
	Jan. 31, 2016		Oct. 31, 2015		Jul. 31, 2015		Apr. 30, 2015		Jan. 31, 2015		Oct. 31, 2014		Jul. 31, 2014		Apr. 30, 2014		Jan. 31, 2016		Jan. 31, 2015		Jan. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Net sales	$ 19,494		$ 64,981		$ 61,072		$ 23,048		$ 25,354		$ 62,273		$ 53,042		$ 23,383		$ 168,595		$ 164,052		$ 155,042
Gross profit	4,210		23,210		23,996		8,194		6,000		20,672		20,696		8,030		59,610		55,398		52,554
Net income (loss)	$ (5,726)		$ 6,003		$ 7,450		$ (3,178)		$ (5,131)		$ 4,632		$ 5,203		$ (3,855)		$ 4,549		$ 849		$ (1,730)
Per common share
Basic (dollar per share)	$ (0.38)	[1]	$ 0.40	[1]	$ 0.50	[1]	$ (0.21)	[1]	$ (0.35)	[1]	$ 0.31	[1]	$ 0.35	[1]	$ (0.26)	[1]	$ 0.31	[2]	$ 0.06	[2]	$ (0.12)	[2]
Assuming dilution (dollar per share)	$ (0.38)	[1]	$ 0.39	[1]	$ 0.49	[1]	$ (0.21)	[1]	$ (0.35)	[1]	$ 0.31	[1]	$ 0.35	[1]	$ (0.26)	[1]	$ 0.30	[2]	$ 0.06	[2]	$ (0.12)	[2]

[1] Net loss per share was calculated based on basic shares outstanding due to the anti-dilutive effect on the inclusion of common stock equivalent shares.

[2] Net loss per share for fiscal year 2014 was calculated based on basic shares outstanding due to the anti-dilutive effect on the inclusion of common stock equivalent shares.