Stock Option Activity and Restricted Share Activity (Detail) (Employee Stock Plan, 2006 Plan, USD $)	9 Months Ended
	Nov. 02, 2013
Employee Stock Plan, 2006 Plan
Number of Shares
Outstanding at beginning of year	376,374
Options granted	2,765,414
Options canceled	(41,425)
Options exercised
Outstanding at end of quarter	3,100,363
Options exercisable at end of quarter	316,435
Weighted-average Exercise price per Option
Outstanding at beginning of year	$ 4.31
Options granted	$ 5.05
Options canceled	$ 4.96
Options exercised
Outstanding at end of quarter	$ 4.96
Options exercisable at end of quarter	$ 4.54
Weighted-average Remaining Contractual Term
Outstanding options at end of quarter	9 years 1 month 6 days
Options exercisable at end of quarter	5 years 7 months 6 days
Aggregate Intrinsic Value
Outstanding options at end of quarter	$ 5,177,325
Options exercisable at end of quarter	$ 693,966