Selected Quarterly Financial Data (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended									12 Months Ended
	Feb. 02, 2013	Oct. 27, 2012	Jul. 28, 2012		Apr. 28, 2012	Jan. 28, 2012	Oct. 29, 2011	Jul. 30, 2011	Apr. 30, 2011	Feb. 02, 2013	Jan. 28, 2012	Jan. 29, 2011
Quarterly Financial Data [Line Items]
Net sales	$ 140,771	$ 124,895	$ 105,101	[1]	$ 96,524	$ 122,929	$ 107,304	$ 87,260	$ 83,131	$ 467,291	$ 400,624	$ 332,604
Gross profit	46,825	41,808	31,144	[1]	30,418	41,357	35,858	25,718	26,209	150,195	129,142	102,615
Operating income (loss)	14,814	13,868	(3,318)	[1]	6,026	14,055	12,344	3,561	4,965	31,390	34,925	24,947
Net income (loss)	$ 9,841	$ 9,294	$ (1,156)	[1]	$ 5,914	$ 13,856	$ 12,155	$ 3,469	$ 4,860	$ 23,893	$ 34,340	$ 24,416
Basic earnings (loss) per share	$ 0.36	$ 0.34	$ (0.04)	[1]	$ 0.30	$ 0.69	$ 0.61	$ 0.17	$ 0.24	$ 0.93	$ 1.72	$ 1.22
Diluted earnings (loss) per share	$ 0.35	$ 0.33	$ (0.04)	[1]	$ 0.29	$ 0.67	$ 0.59	$ 0.17	$ 0.24	$ 0.92	$ 1.68	$ 1.21

[1] As discussed in Notes 1, 2 and 14 to the Consolidated Financial Statements, during the second quarter of fiscal year 2012 (fiscal year ended February 2, 2013) the Company converted from an "S" Corporation to a "C" Corporation for income tax purposes. Also during that quarter, as discussed in Note 12 to the Consolidated Financial Statements, the Company recognized $7.6 million of compensation expense related to stock options that became exercisable upon the consummation of the Company's May 3, 2012 IPO.