Stock-Based Compensation - Options Outstanding, both Exercisable and Unexercisable (Detail) (USD $)	12 Months Ended
	Jan. 31, 2014
Options outstanding, both exercisable and unexercisable
Options outstanding and exercisable, Aggregate intrinsic value
Range: $1.69 to $4.99
Options outstanding, both exercisable and unexercisable
Options outstanding and exercisable, Number of Options	182,967
Options outstanding and exercisable, Weighted-average exercise price	$ 3.18
Options outstanding and exercisable, Weighted-average remaining contractual life	5 years 7 days
Options outstanding and exercisable, Aggregate intrinsic value
Options outstanding and unexercisable, Number of Options	117,006
Options outstanding and unexercisable, Weighted-average exercise price	$ 2.62
Options outstanding and unexercisable, Weighted-average remaining contractual life	8 years 4 months 24 days
Options outstanding and unexercisable, Aggregate intrinsic value
Range: $5.00 to $8.70
Options outstanding, both exercisable and unexercisable
Options outstanding and exercisable, Number of Options	180,756
Options outstanding and exercisable, Weighted-average exercise price	$ 6.79
Options outstanding and exercisable, Weighted-average remaining contractual life	3 years 9 months 29 days
Options outstanding and exercisable, Aggregate intrinsic value
Options outstanding and unexercisable, Number of Options	40,048
Options outstanding and unexercisable, Weighted-average exercise price	$ 6.57
Options outstanding and unexercisable, Weighted-average remaining contractual life	6 years 9 months 15 days
Options outstanding and unexercisable, Aggregate intrinsic value