Options Granted under Stock Option Plans (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	May 02, 2015
Number of Shares
Options outstanding at beginning of year	5,569
Granted	682
Exercised	(1,000)
Expired or cancelled	(49)
Options outstanding at end of year	5,202
Options exercisable at end of year	3,685
Options vested and expected to vest	5,144
Options available for future grant at end of year	13,041
Weighted-Average Term
Options outstanding at end of year	6 years 8 months 5 days
Options exercisable at end of year	5 years 8 months 1 day
Options vested and expected to vest	6 years 7 months 24 days
Weighted-Average Exercise Price
Options outstanding at beginning of year	$ 25.89
Granted	$ 62.11
Exercised	$ 22.84
Expired or cancelled	$ 48.47
Options outstanding at end of year	$ 31.01
Options exercisable at end of year	$ 23.09
Options vested and expected to vest	$ 30.73