Comprehensive Income (AOCI components) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jan. 24, 2015	Jan. 25, 2014	Jul. 26, 2014
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI Balance			$ 677
AOCI Balance	186		677
Net Unrealized Gains on Investments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI Balance	424	379
Other comprehensive income (loss) before reclassifications attributable to Cisco Systems, Inc.	(23)	332
(Gains) losses reclassified out of other comprehensive income	(76)	(165)
Tax benefit (expense)	49	(60)
AOCI Balance	374	486
Net Unrealized Gains (Losses) Cash Flow Hedging Instruments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI Balance	(12)	8
Other comprehensive income (loss) before reclassifications attributable to Cisco Systems, Inc.	(131)	33
(Gains) losses reclassified out of other comprehensive income	30	(28)
Tax benefit (expense)	3	(2)
AOCI Balance	(110)	11
Cumulative Translation Adjustment and Actuarial Gains (Losses)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI Balance	265	221
Other comprehensive income (loss) before reclassifications attributable to Cisco Systems, Inc.	(379)	(14)
(Gains) losses reclassified out of other comprehensive income	0	0
Tax benefit (expense)	36	(1)
AOCI Balance	(78)	206
Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI Balance	677	608
Other comprehensive income (loss) before reclassifications attributable to Cisco Systems, Inc.	(533)	351
(Gains) losses reclassified out of other comprehensive income	(46)	(193)
Tax benefit (expense)	88	(63)
AOCI Balance	$ 186	$ 703