Options Granted under Stock Option Plans (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Apr. 28, 2012 Year
Shares
Options outstanding at the beginning of the year	7,227
Granted	930
Exercised	(826)
Expired or cancelled	(24)
Options outstanding, Ending Balance	7,307
Options exercisable, Ending Balance	4,838
Options available for future grant, Ending Balance	5,619
Weighted-Average Term
Options outstanding at end of period	6.33
Options exercisable at end of period	4.94
Weighted-Average Exercise Price
Weighted Average Exercise Price, Beginning Balance	$ 18.44
Granted	$ 30.92
Exercised	$ 17.60
Expired or cancelled	$ 22.22
Weighted Average Exercise Price, Ending Balance	$ 20.11
Weighted Average Exercise Price Exercisable, Ending Balance	$ 18.83