Comprehensive Income (Reclassification out of other comprehensive income) (Details) - USD ($) $ in Millions	3 Months Ended
	Oct. 24, 2015	Oct. 25, 2014
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	$ (1)	$ 7
Derivatives designated as cash flow hedging instruments:
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Total amounts reclassified out of AOCI	(3)	(4)
Derivatives designated as cash flow hedging instruments: | Operating expenses
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Total amounts reclassified out of AOCI	(2)	(3)
Derivatives designated as cash flow hedging instruments: | Cost of sales—service
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Total amounts reclassified out of AOCI	(1)	(1)
Cumulative translation adjustment and Actuarial gains and losses [Member] | Operating expenses
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Total amounts reclassified out of AOCI	(1)	0
Total Cisco Shareholders’ Equity
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Total amounts reclassified out of AOCI	$ (5)	$ 3