Acquisitions and Divestitures (Summary Of Allocation Of Total Purchase Consideration) (Details) $ in Millions	9 Months Ended
	Apr. 30, 2016 USD ($) acquisitions
Business Acquisition [Line Items]
Number of business combinations (in numbers) | acquisitions	12
Purchase Consideration	$ 3,378
Net Tangible Assets Acquired (Liabilities Assumed)	(124)
Purchased Intangible Assets	940
Goodwill	2,562
MaintenanceNet
Business Acquisition [Line Items]
Purchase Consideration	105
Net Tangible Assets Acquired (Liabilities Assumed)	(21)
Purchased Intangible Assets	65
Goodwill	61
OpenDNS
Business Acquisition [Line Items]
Purchase Consideration	545
Net Tangible Assets Acquired (Liabilities Assumed)	(9)
Purchased Intangible Assets	61
Goodwill	493
Lancope
Business Acquisition [Line Items]
Purchase Consideration	410
Net Tangible Assets Acquired (Liabilities Assumed)	(34)
Purchased Intangible Assets	121
Goodwill	323
Acano
Business Acquisition [Line Items]
Purchase Consideration	528
Net Tangible Assets Acquired (Liabilities Assumed)	(27)
Purchased Intangible Assets	103
Goodwill	452
Leaba
Business Acquisition [Line Items]
Purchase Consideration	219
Net Tangible Assets Acquired (Liabilities Assumed)	(18)
Purchased Intangible Assets	96
Goodwill	141
Jasper
Business Acquisition [Line Items]
Purchase Consideration	1,234
Net Tangible Assets Acquired (Liabilities Assumed)	5
Purchased Intangible Assets	361
Goodwill	868
CliQr
Business Acquisition [Line Items]
Purchase Consideration	225
Net Tangible Assets Acquired (Liabilities Assumed)	(3)
Purchased Intangible Assets	69
Goodwill	$ 159
Others (five in total)
Business Acquisition [Line Items]
Number of business combinations (in numbers)	5
Purchase Consideration	$ 112
Net Tangible Assets Acquired (Liabilities Assumed)	(17)
Purchased Intangible Assets	64
Goodwill	$ 65