Consolidated Statements Of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Apr. 29, 2017	Apr. 30, 2016	Apr. 29, 2017	Apr. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 2,515	$ 2,349	$ 7,185	$ 7,926
Available-for-sale investments:
Change in net unrealized gains and losses, net of tax benefit (expense) of $(25) and $129 for the three and nine months ended April 29, 2017, respectively, and $(146) and $59 for the corresponding periods of fiscal 2016, respectively	229	217	(168)	(95)
Net (gains) losses reclassified into earnings, net of tax (benefit) expense of $(32) and $(38) for the three and nine months ended April 29, 2017, respectively, and $(2) and $(9) for the corresponding periods of fiscal 2016, respectively	44	4	53	17
Total- Available-for-sale investments	273	221	(115)	(78)
Cash flow hedging instruments:
Change in unrealized gains and losses, net of tax benefit (expense) of $(5) and $(1) for the three and nine months ended April 29, 2017, respectively, and $(2) and $2 for the corresponding periods of fiscal 2016, respectively	20	19	(24)	(1)
Net (gains) losses reclassified into earnings, net of tax (benefit) expense of $(2) and $(5) for the three and nine months ended April 29, 2017, respectively, and $(2) and $(4) for the corresponding periods of fiscal 2016, respectively	25	7	61	13
Total- Cash flow hedging instruments	45	26	37	12
Net change in cumulative translation adjustment and actuarial gains and losses net of tax benefit (expense) of $(6) and $(7) for the three and nine months ended April 29, 2017, respectively, and $(9) and $(43) for the corresponding periods of fiscal 2016, respectively	134	326	63	(231)
Other comprehensive income (loss)	452	573	(15)	(297)
Comprehensive income	2,967	2,922	7,170	7,629
Comprehensive (income) loss attributable to noncontrolling interests	7	7	(1)	9
Comprehensive income attributable to Cisco Systems, Inc.	$ 2,974	$ 2,929	$ 7,169	$ 7,638