Computations of Basic and Diluted Net Income Per Share (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jul. 28, 2012	Jul. 30, 2011	Jul. 28, 2012	Jul. 30, 2011
Numerator:
Net income	$ 93,074	$ 192,392	$ 187,617	$ 339,253
Denominator:
Weighted average common shares outstanding	562,362	608,511	571,193	623,728
Effect of dilutive securities:
Common share-based awards	7,963	14,621	11,339	16,408
Weighted average shares - diluted	570,325	623,132	582,532	640,136
Net income per share:
Basic	$ 0.17	$ 0.32	$ 0.33	$ 0.54
Diluted	$ 0.16	$ 0.31	$ 0.32	$ 0.53
Stock Options
Net income per share:
Weighted average shares outstanding from stock options	29,488	22,447	26,553	19,218
Weighted-average exercise price:	$ 17.52	$ 18.59	$ 17.86	$ 19.19