Goodwill and Purchased Intangible Assets (Schedule Of Amortization Of Purchased Intangible Assets) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jan. 24, 2015	Jan. 25, 2014	Jan. 24, 2015	Jan. 25, 2014
Acquired Intangible Asset Amortization by Statement of Operations Class [Line Items]
Amortization of purchased intangible assets	$ 72	$ 71	$ 143	$ 136
Cost of sales
Acquired Intangible Asset Amortization by Statement of Operations Class [Line Items]
Amortization of purchased intangible assets	242	189	431	363
Operating expenses
Acquired Intangible Asset Amortization by Statement of Operations Class [Line Items]
Amortization of purchased intangible assets	72	71	143	136
Total
Acquired Intangible Asset Amortization by Statement of Operations Class [Line Items]
Amortization of purchased intangible assets	$ 314	$ 260	$ 574	$ 499