Borrowings (Schedule Of Long-Term Debt) (Detail) (USD $) In Millions, unless otherwise specified	Oct. 27, 2012	Jul. 28, 2012
Long-term debt before Unaccreted discount and Hedge accounting adjustment	$ 16,000	$ 16,000
Unaccreted discount	(68)	(70)
Hedge accounting fair value adjustments	330	357
Total long-term debt	16,272	16,297
Floating-Rate Notes, Due 2014 [Member]
Senior notes	1,250	1,250
Effective rate	0.71%	0.81%
1.625% Fixed-Rate Notes, Due 2014 [Member]
Debt Instrument, Interest Rate, Stated Percentage	1.625%
Senior notes	2,000	2,000
Effective rate	0.76%	0.84%
2.90% Fixed-Rate Notes, Due 2014 [Member]
Debt Instrument, Interest Rate, Stated Percentage	2.90%
Senior notes	500	500
Effective rate	3.11%	3.11%
5.50% Fixed-Rate Notes, Due 2016 [Member]
Debt Instrument, Interest Rate, Stated Percentage	5.50%
Senior notes	3,000	3,000
Effective rate	3.14%	3.16%
3.15% Fixed-Rate Notes, Due 2017 [Member]
Debt Instrument, Interest Rate, Stated Percentage	3.15%
Senior notes	750	750
Effective rate	0.96%	1.03%
4.95% Fixed-Rate Notes, Due 2019 [Member]
Debt Instrument, Interest Rate, Stated Percentage	4.95%
Senior notes	2,000	2,000
Effective rate	5.08%	5.08%
4.45% Fixed-Rate Notes, Due 2020 [Member]
Debt Instrument, Interest Rate, Stated Percentage	4.45%
Senior notes	2,500	2,500
Effective rate	4.50%	4.50%
5.90% Fixed-Rate Notes, Due 2039 [Member]
Debt Instrument, Interest Rate, Stated Percentage	5.90%
Senior notes	2,000	2,000
Effective rate	6.11%	6.11%
5.50% Fixed-Rate Notes, Due 2040 [Member]
Debt Instrument, Interest Rate, Stated Percentage	5.50%
Senior notes	2,000	2,000
Effective rate	5.67%	5.67%
Other Long Term Debt [Member]
Other Long-term Debt	$ 10	$ 10
Effective rate	0.19%	0.19%