Stock Option Activity under Two Thousand Six Plan (Detail) (USD $)	9 Months Ended
	Nov. 01, 2014		Nov. 02, 2013
Number of Shares
Options granted	141,684		2,765,414
Employee Stock Plan, 2006 Plan
Number of Shares
Outstanding options at beginning of year	2,721,569
Options granted	141,684
Options canceled	(87,306)
Options exercised	(26,224)	[1]
Outstanding options at end of quarter	2,749,723
Options exercisable at end of quarter	338,810
Weighted-average exercise price per option
Outstanding options at beginning of year	$ 4.95
Options granted	$ 5.29
Options canceled	$ 5.04
Options exercised	$ 4.69	[1]
Outstanding options at end of quarter	$ 4.97
Options exercisable at end of quarter	$ 4.55
Weighted-average remaining contractual term
Outstanding options at end of quarter	8 years 4 months 24 days
Options exercisable at end of quarter	5 years 2 months 12 days
Aggregate Intrinsic Value
Outstanding options at end of quarter	$ 862,978
Options exercisable at end of quarter	$ 341,453

[1] The intrinsic value of options exercised was immaterial.