Borrowings - Additional Information (Detail) (USD $)	12 Months Ended
	Jul. 27, 2013	Jul. 28, 2012
Debt Instrument [Line Items]
Short Term Debt Financing Program Maximum Value	$ 3,000,000,000
Commercial paper notes outstanding	0	0
Derivative, Notional Amount	12,992,000,000	14,410,000,000
Line of Credit Facility, Interest Rate Description	either (i) the higher of the Federal Funds rate plus 0.50%, Bank of America's "prime rate" as announced from time to time, or one-month LIBOR plus 1.00%, or (ii) LIBOR plus a margin
Senior Notes [Member]
Debt Instrument [Line Items]
Derivative, Notional Amount	5,250,000,000
Unsecured Debt [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity	3,000,000,000
Maturity date	Feb. 17, 2017
Interest Rate-Federal Funds rate plus 0.50%	0.50%
Interest rate-one-month LIBOR plus 1.00%	1.00%
Additional credit facility upon agreement	$ 2,000,000,000
Debt extension date [Member]
Debt Instrument [Line Items]
Maturity date	Feb. 17, 2019