Comprehensive Income (AOCI Components) (Details) (USD $) In Millions, unless otherwise specified			3 Months Ended		9 Months Ended				3 Months Ended		9 Months Ended
	Apr. 26, 2014	Jul. 27, 2013	Apr. 26, 2014 Parent	Apr. 27, 2013 Parent	Apr. 26, 2014 Parent	Apr. 27, 2013 Parent	Apr. 26, 2014 Available-for-sale Securities	Apr. 27, 2013 Available-for-sale Securities	Apr. 26, 2014 Derivative	Apr. 27, 2013 Derivative	Apr. 26, 2014 Derivative	Apr. 27, 2013 Derivative	Apr. 26, 2014 Accumulated Translation Adjustment	Apr. 27, 2013 Accumulated Translation Adjustment
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ 697	$ 608			$ 608	$ 661	$ 379	$ 409			$ 8	$ (53)	$ 221	$ 305
OCI, Unrealized Holding Gain (Loss) on Securities Arising During Period, before Reclassification & Tax							339	22
Amount Reclassified Out of OCI, Before Tax							(234)	(46)
OCI, Unrealized Gain (Loss) on Derivatives Arising During Period, before Reclassification & Tax											46	59
Amount Reclassified Out of OCI, Before Tax									(16)	(4)	(44)	(7)
OCI, Foreign Currency Transaction and Translation Gain (Loss), before Reclassification and Tax													32	6
Amount Reclassified Out of OCI, Before Tax													0	0
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent					417	87
Amount Reclassified Out of OCI, Before Tax			(85)	(10)	(278)	(53)
Tax benefit (expense)					(50)	(6)	(43)	9			(2)	(1)	(5)	(14)
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ 697	$ 608	$ 697	$ 689	$ 697	$ 689	$ 441	$ 394	$ 8	$ (2)	$ 8	$ (2)	$ 248	$ 297