Share Repurchases - Additional Information (Detail) (USD $)	1 Months Ended		3 Months Ended	16 Months Ended
	Feb. 25, 2012	Jan. 28, 2012	Jul. 28, 2012	Nov. 26, 2011	Feb. 23, 2012	Jul. 30, 2011
Share Repurchases [Line Items]
Share repurchases, authorized amount	$ 1,000,000,000			$ 3,250,000,000
Share repurchases, amount cancelled					441,000,000
Share repurchases, remaining amount		443,000,000	635,000,000
Total share repurchases, unpaid amount		$ 4,000,000	$ 2,000,000			$ 8,000,000