Comprehensive Income (AOCI components) (Details) - USD ($) $ in Millions	9 Months Ended
	Apr. 30, 2016	Apr. 25, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI Balance	$ 61
AOCI Balance	(227)
Net Unrealized Gains on Available-for-Sale Investments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI Balance	310	$ 424
Other comprehensive income (loss) before reclassifications attributable to Cisco Systems, Inc.	(145)	111
(Gains) losses reclassified out of AOCI	26	(120)
Tax benefit (expense)	50	8
AOCI Balance	241	423
Net Unrealized Losses Cash Flow Hedging Instruments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI Balance	(16)	(12)
Other comprehensive income (loss) before reclassifications attributable to Cisco Systems, Inc.	(3)	(163)
(Gains) losses reclassified out of AOCI	17	94
Tax benefit (expense)	(2)	3
AOCI Balance	(4)	(78)
Cumulative Translation Adjustment and Actuarial Gains and Losses
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI Balance	(233)	265
Other comprehensive income (loss) before reclassifications attributable to Cisco Systems, Inc.	(190)	(473)
(Gains) losses reclassified out of AOCI	2	0
Tax benefit (expense)	(43)	50
AOCI Balance	(464)	(158)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI Balance	61	677
Other comprehensive income (loss) before reclassifications attributable to Cisco Systems, Inc.	(338)	(525)
(Gains) losses reclassified out of AOCI	45	(26)
Tax benefit (expense)	5	61
AOCI Balance	$ (227)	$ 187