Borrowings (Schedule Of Long-Term Debt) (Detail) (USD $) In Millions, unless otherwise specified	Jul. 27, 2013	Jul. 28, 2012
Debt Instrument [Line Items]
Other long-term debt	$ 21	$ 10
Long-term debt before Unaccreted discount and Hedge accounting adjustment	16,021	16,010
Unaccreted discount	(65)	(70)
Hedge accounting fair value adjustments	245	357
Long-term Debt, Noncurrent Portion	16,201	16,297
Current portion of long-term debt	3,273	0
Long-term debt	12,928	16,297
Floating-rate notes, due 2014
Debt Instrument [Line Items]
Senior Notes	1,250	1,250
Effective Rate	0.62%	0.81%
1.625% fixed-rate notes, due 2014
Debt Instrument [Line Items]
Senior Notes	2,000	2,000
Effective Rate	0.64%	0.84%
2.90% fixed-rate notes, due 2014
Debt Instrument [Line Items]
Senior Notes	500	500
Effective Rate	3.11%	3.11%
5.50% fixed-rate notes, due 2016
Debt Instrument [Line Items]
Senior Notes	3,000	3,000
Effective Rate	3.07%	3.16%
3.15% fixed-rate notes, due 2017
Debt Instrument [Line Items]
Senior Notes	750	750
Effective Rate	0.84%	1.03%
4.95% fixed-rate notes, due 2019
Debt Instrument [Line Items]
Senior Notes	2,000	2,000
Effective Rate	4.70%	5.08%
4.45% fixed-rate notes, due 2020
Debt Instrument [Line Items]
Senior Notes	2,500	2,500
Effective Rate	4.15%	4.50%
5.90% fixed-rate notes, due 2039
Debt Instrument [Line Items]
Senior Notes	2,000	2,000
Effective Rate	6.11%	6.11%
5.50% fixed-rate notes, due 2040
Debt Instrument [Line Items]
Senior Notes	$ 2,000	$ 2,000
Effective Rate	5.67%	5.67%
Other long-term debt
Debt Instrument [Line Items]
Effective Rate	1.46%	0.19%