Comprehensive Income (Reclassification out of other comprehensive income) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Jul. 26, 2014	Jul. 27, 2013	Jul. 28, 2012
Net Unrealized Gains on 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	$ 300	$ 48	$ 101
Derivatives designated as cash flow hedging instruments:
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Total amounts reclassified out of other comprehensive income	68	12	(72)
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 other comprehensive income	55	10	(59)
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 other comprehensive income	13	2	(14)
Derivatives designated as cash flow hedging instruments: | Interest expense
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Total amounts reclassified out of other comprehensive income	0	0	1
Total Cisco Shareholders’ Equity
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Total amounts reclassified out of other comprehensive income	$ 368	$ 60	$ 29