Comprehensive Income (Reclassification out of other comprehensive income) (Details) - USD ($) $ in Millions	12 Months Ended
	Jul. 25, 2015	Jul. 26, 2014	Jul. 27, 2013
Net Unrealized Gains on Available-for-Sale Investments | Other income (loss), net
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Net unrealized gains on available-for-sale investments	$ 157	$ 300	$ 48
Cash Flow Hedges
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Total amounts reclassified out of AOCI	(154)	68	12
Cash Flow Hedges | Operating expenses
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Total amounts reclassified out of AOCI	(121)	55	10
Cash Flow Hedges | Cost of sales—service
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Total amounts reclassified out of AOCI	(33)	13	2
Cumulative translation adjustment and Actuarial gains and losses | Operating expenses
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Total amounts reclassified out of AOCI	(2)	0	0
Total Cisco Shareholders’ Equity
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Total amounts reclassified out of AOCI	$ 1	$ 368	$ 60