Fair Value (Additional Information) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Apr. 30, 2016	Apr. 25, 2015	Apr. 30, 2016	Apr. 25, 2015	Jul. 25, 2015
Fair Value Measurements [Line Items]
Senior notes, carrying value	$ 28,594		$ 28,594		$ 25,351
Level 2
Fair Value Measurements [Line Items]
Senior notes, fair value	30,600		30,600		26,600
Senior notes, carrying value	28,600		28,600		25,400
Level 3
Fair Value Measurements [Line Items]
Gains (losses) for assets measured on a nonrecurring basis	14	$ 23	107	$ 82
Long term loan receivables and financed service contracts and others carrying value	2,400		2,400		2,200
Remaining carrying value of impaired investments | Level 3
Fair Value Measurements [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	20	4	20	4
Remaining carrying value of impaired purchased intangibles | Level 3
Fair Value Measurements [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	0	0	0	0
Remaining carrying value of property held for sale
Fair Value Measurements [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	0	$ 11	0	$ 11
Investments In Privately Held Companies
Fair Value Measurements [Line Items]
Carrying Value, Cost Method Investments	$ 367		$ 367		$ 319