Fair Value - Additional Information (Detail) (USD $)			3 Months Ended	9 Months Ended			3 Months Ended	9 Months Ended
	Apr. 26, 2014	Jul. 27, 2013	Apr. 27, 2013 Fair Value, Inputs, Level 3 [Member]	Apr. 27, 2013 Fair Value, Inputs, Level 3 [Member]	Apr. 26, 2014 Fair Value, Inputs, Level 3 [Member]	Jul. 27, 2013 Fair Value, Inputs, Level 3 [Member]	Apr. 27, 2013 Fair Value, Inputs, Level 3 [Member] Investments In Privately Held Companies Fair Value Assets Measured On Nonrecurring Basis Change In Unrealized Gain Loss Included In Interest And Other Income Net [Member]	Apr. 26, 2014 Fair Value, Inputs, Level 3 [Member] Investments In Privately Held Companies Fair Value Assets Measured On Nonrecurring Basis Change In Unrealized Gain Loss Included In Interest And Other Income Net [Member]	Apr. 27, 2013 Fair Value, Inputs, Level 3 [Member] Investments In Privately Held Companies Fair Value Assets Measured On Nonrecurring Basis Change In Unrealized Gain Loss Included In Interest And Other Income Net [Member]	Apr. 26, 2014 Fair Value, Inputs, Level 2 [Member]	Jul. 27, 2013 Fair Value, Inputs, Level 2 [Member]
Other Fair Value Disclosures [Line Items]
Gains (Losses) for the Period			$ (73,000,000)	$ (55,000,000)			$ 5,000,000	$ 10,000,000	$ 23,000,000
Carrying Value, Cost Method Investments	273,000,000	242,000,000
Loan Receivables, Financed Service Contracts And Others, Carrying Value					1,700,000,000	2,100,000,000
Long-term Debt, Fair Value										22,400,000,000	17,600,000,000
Long-term Debt, carrying value	$ 20,884,000,000	$ 16,201,000,000								$ 20,900,000,000	$ 16,200,000,000