Borrowings - Additional Information (Detail) (USD $)	3 Months Ended
	Oct. 26, 2013	Jul. 27, 2013
Debt Instrument [Line Items]
ST debt financing program- Commercial paper notes	$ 3,000,000,000
Commercial Paper Outstanding	0	0
Notional amount of derivatives	12,800,000,000	12,992,000,000
Unsecured Debt [Member]
Debt Instrument [Line Items]
Unsecured Revolving Credit Facility	3,000,000,000
Unsecured revolving credit facility maturity date	Feb. 17, 2017
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 that is based on the Company's senior debt credit ratings
Interest Rate- Federal Funds rate plus 0.5%	0.50%
Interest Rate- One-month LIBOR plus 1.00%	1.00%
Available increases under the credit facility	2,000,000,000
Additional unsecured revolving credit facility maturity date	Feb. 17, 2019
Designated as Hedging Instrument [Member] | Interest Rate Derivatives [Member]
Debt Instrument [Line Items]
Notional amount of derivatives	$ 5,750,000,000	$ 5,250,000,000