Quarterly Results (Unaudited) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended																12 Months Ended
	Jan. 31, 2013		Oct. 31, 2012		Jul. 31, 2012		Apr. 30, 2012		Jan. 31, 2012		Oct. 31, 2011		Jul. 31, 2011		Apr. 30, 2011		Jan. 31, 2013		Jan. 31, 2012		Jan. 31, 2011
Quarterly Financial Information Disclosure [Abstract]
Net sales	$ 18,154		$ 56,642		$ 60,392		$ 23,668		$ 26,294		$ 53,074		$ 62,817		$ 24,256		$ 158,856		$ 166,441		$ 180,995
Gross profit	2,400		19,318		22,867		6,967		5,457		16,041		19,882		6,778		51,552		48,158		51,374
Net income (loss)	$ (8,958)		$ 2,908		$ 7,053		$ (4,833)		$ (7,836)		$ (3,299)		$ 2,732		$ (5,400)		$ (3,830)		$ (13,803)		$ (17,594)
Per common share
Basic (dollar per share)	$ (0.62)	[1]	$ 0.20	[1]	$ 0.49	[1]	$ (0.34)	[1]	$ (0.55)	[1]	$ (0.23)	[1]	$ 0.19	[1]	$ (0.38)	[1]	$ (0.27)	[1]	$ (0.97)	[1]	$ (1.25)	[1]
Assuming dilution (dollar per share)	$ (0.62)	[1]	$ 0.20	[1]	$ 0.49	[1]	$ (0.34)	[1]	$ (0.55)	[1]	$ (0.23)	[1]	$ 0.19	[1]	$ (0.38)	[1]	$ (0.27)	[1]	$ (0.97)	[1]	$ (1.25)	[1]

[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.