Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Jul. 29, 2017	Jul. 30, 2016	Jul. 25, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 9,609	$ 10,739	$ 8,981
Available-for-sale investments:
Change in net unrealized gains and losses, net of tax benefit (expense) of $74, $(49), and $14 for fiscal 2017, 2016, and 2015, respectively	(89)	92	(12)
Net (gains) losses reclassified into earnings, net of tax expense (benefit) of $(37), $0, and $57 for fiscal 2017, 2016, and 2015, respectively	50	1	(100)
Total- Available-for-sale investments	(39)	93	(112)
Cash flow hedging instruments:
Change in unrealized gains and losses, net of tax benefit (expense) of $(5), $7, and $19 for fiscal 2017, 2016, and 2015, respectively	17	(59)	(140)
Net (gains) losses reclassified into earnings, net of tax (benefit) expense of $(5), $(4), and $(18) for fiscal 2017, 2016, and 2015, respectively	74	16	136
Total- Cash flow hedging instruments	91	(43)	(4)
Net change in cumulative translation adjustment and actuarial gains and losses, net of tax benefit (expense) of $(13), $(42), and $63 for fiscal 2017, 2016, and 2015, respectively	321	(447)	(498)
Other comprehensive income (loss)	373	(397)	(614)
Comprehensive income	9,982	10,342	8,367
Comprehensive (income) loss attributable to noncontrolling interests	(1)	10	(2)
Comprehensive income attributable to Cisco Systems, Inc.	$ 9,981	$ 10,352	$ 8,365