Quarterly Financial Data (Unaudited) - Schedule of Quarterly Financial Data (Unaudited) (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Jan. 31, 2014	Oct. 31, 2013	Jul. 31, 2013	Apr. 30, 2013	Jan. 31, 2013	Oct. 31, 2012	Jul. 31, 2012	Apr. 30, 2012	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2012
Quarterly Financial Information Disclosure [Abstract]
Net revenues:	$ 23,647	$ 20,275	$ 20,895	$ 27,291	$ 28,401	$ 18,574	$ 23,080	$ 34,630	$ 92,108	$ 104,685	$ 112,834
Gross profit:	8,165	4,953	4,300	14,597	8,773	4,353	7,400	16,887	32,015	37,413	57,752
Income (loss) before income taxes:	2,179	(3,106)	(966)	7,919	3,365	(2,178)	1,274	11,063	6,026	13,524	34,330
Incomes taxes (benefit):	397	(478)	(273)	1,612	(50)	(956)	(5,128)	2,607	1,258	(3,527)	10,009
Net income (loss):	$ 1,782	$ (2,628)	$ (693)	$ 6,307	$ 3,415	$ (1,222)	$ 6,402	$ 8,456	$ 4,768	$ 17,051	$ 24,321
Income per common share-basic:	$ 0.14	$ (0.21)	$ (0.05)	$ 0.49	$ 0.27	$ (0.10)	$ 0.50	$ 0.67	$ 0.37	$ 1.34	$ 2.13
Income per common share-diluted:	$ 0.14	$ (0.21)	$ (0.05)	$ 0.48	$ 0.26	$ (0.10)	$ 0.48	$ 0.63	$ 0.36	$ 1.29	$ 2.02