Stock-Based Compensation - Summary of Change in Number of Non-Vested Options to Purchase Shares of Common Stock (Detail) (USD $)	3 Months Ended	6 Months Ended
	Jul. 31, 2014	Jul. 31, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Shares, Nonvested, Beginning balance		303,000
Shares, Granted	0	180,500
Shares, Vested		(81,000)
Shares, Nonvested, Ending balance	402,500	402,500
Weighted Average Fair Value, Nonvested, Beginning balance		$ 4.40
Weighted Average Fair Value, Granted		$ 6.28
Weighted Average Fair Value, Vested		$ 3.30
Weighted Average Fair Value, Nonvested, Ending balance	$ 5.46	$ 5.46