Borrowings (Short-Term Debt) (Detail) (USD $) In Millions, unless otherwise specified	Jan. 25, 2014	Jul. 27, 2013
Short-term Debt [Line Items]
Debt, Current	$ 4,762	$ 3,283
Senior Notes
Short-term Debt [Line Items]
Debt, Current	3,752	3,273
Short-term debt, weighted-average interest rate	0.93%	0.63%
Commercial Paper [Member]
Short-term Debt [Line Items]
Debt, Current	1,000	0
Short-term debt, weighted-average interest rate	0.12%	0.00%
Short-term Debt [Member]
Short-term Debt [Line Items]
Debt, Current	$ 10	$ 10
Short-term debt, weighted-average interest rate	2.55%	2.52%