Summary of Stock Option Activity (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	6 Months Ended
	Jul. 28, 2012
Options
Outstanding - beginning	11,197
Granted	1,046
Exercised	(1,946)	[1]
Cancelled	(597)
Outstanding- Ending	9,700
Vested and expected to vest-ending	9,579
Exercisable-ending	6,425	[2]
Weighted-Average Exercise Price
Outstanding-beginning	$ 15.31
Granted	$ 14.26
Exercised	$ 9.55	[1]
Cancelled	$ 14.62
Outstanding-ending	$ 16.39
Vested and expected to vest-ending	$ 16.41
Exercisable-ending	$ 13.88	[2]
Weighted-Average Remaining Contractual Term (In years)
Outstanding-ending	2 years 2 months 12 days
Vested and expected to vest-ending	2 years 2 months 12 days
Exercisable-ending	1 year 8 months 12 days	[2]
Aggregate Intrinsic Value
Outstanding-ending	$ 55,957
Vested and expected to vest-ending	55,261
Exercisable-ending	$ 45,242	[2]

[1] Options exercised during the 26 weeks ended July 28, 2012 had exercise prices ranging from $4.54 to $20.62.

[2] Options exercisable represent "in-the-money" vested options based upon the weighted average exercise price of vested options compared to the Company's stock price at July 28, 2012.