Stock-Based Compensation - Summary of Change in Number of Non-Vested Options to Purchase Shares of Common Stock (Detail) (USD $)	12 Months Ended
	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2012
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Shares, Nonvested, Beginning balance	388,500	212,500	237,000
Shares, Granted	303,000	293,000	212,500
Shares, Vested	(384,500)	(112,000)	(232,000)
Shares, Forfeited (non-vested)	(4,000)	(5,000)	(5,000)
Shares, Nonvested, Ending balance	303,000	388,500	212,500
Weighted Average Fair Value, Nonvested, Beginning balance	$ 5.67	$ 5.09	$ 6.31
Weighted Average Fair Value, Granted	$ 4.40	$ 5.65	$ 5.09
Weighted Average Fair Value, Vested	$ 5.67	$ 4.51	$ 6.34
Weighted Average Fair Value, Forfeited (non-vested)	$ 5.71	$ 6.32	$ 4.98
Weighted Average Fair Value, Nonvested, Ending balance	$ 4.40	$ 5.67	$ 5.09