Borrowings (Schedule Of Short-Term Debt) (Detail) (USD $) In Millions, unless otherwise specified	Jul. 28, 2012	Jul. 30, 2011
Short-term Debt [Line Items]
Short-term debt	$ 31	$ 588
Short-term debt, Weighted-Average Interest Rate
Commercial Paper
Short-term Debt [Line Items]
Short-term debt		500
Short-term debt, Weighted-Average Interest Rate		0.14%
Other Notes and Borrowings
Short-term Debt [Line Items]
Short-term debt	$ 31	$ 88
Interest rate other short term borrowings	6.72%	4.59%