Comprehensive Income (Reclassified Out of Other Comprehensive Income) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Apr. 26, 2014	Apr. 27, 2013	Apr. 26, 2014	Apr. 27, 2013
Parent
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amount Reclassified Out of OCI, Before Tax	$ 85	$ 10	$ 278	$ 53
Available-for-sale Securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amount Reclassified Out of OCI, Before Tax			234	46
Available-for-sale Securities | Other income (loss), net
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amount Reclassified Out of OCI, Before Tax	69	6	234	46
Derivative
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amount Reclassified Out of OCI, Before Tax	16	4	44	7
Derivative | Operating Expenses
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amount Reclassified Out of OCI, Before Tax	13	3	36	5
Derivative | Cost Of Sales-Service
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amount Reclassified Out of OCI, Before Tax	$ 3	$ 1	$ 8	$ 2