Share-Based Compensation - Summary of Stock Option Activity for Both Employees and Non-employees (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Jan. 28, 2017	Jan. 30, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Options, Outstanding at beginning of period	2,879,735
Stock Options, Granted	725,451
Stock Options, Exercised	(807,545)
Stock Options, Forfeited or expired	(538,854)
Stock Options, Outstanding at end of period	2,258,787	2,879,735
Stock Options, Vested and exercisable at January 28, 2017	605,937
Weighted Average Exercise Price, Outstanding at beginning of period	$ 4.61
Weighted Average Exercise Price, Granted	5.77
Weighted Average Exercise Price, Exercised	5.79
Weighted Average Exercise Price, Forfeited or expired	4.75
Weighted Average Exercise Price, Outstanding at end of period	4.53	$ 4.61
Weighted Average Exercise Price, Vested and exercisable at January 28, 2017	$ 4.24
Weighted Average Remaining Contractual Term (years), Outstanding	8 years 10 months 24 days	8 years 8 months 12 days
Weighted Average Remaining Contractual Term (years), Outstanding, Vested and exercisable at January 28, 2017	8 years 9 months 18 days
Aggregate Intrinsic Value, Outstanding		$ 2,402
Aggregate Intrinsic Value, Vested and exercisable at January 28, 2017	$ 0