Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	12 Months Ended
	Jul. 28, 2018	Jul. 29, 2017	Jul. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 110	$ 9,609	$ 10,739
Available-for-sale investments:
Change in net unrealized gains and losses, net of tax benefit (expense) of $(11), $74, and $(49) for fiscal 2018, 2017, and 2016, respectively	(554)	(89)	92
Net (gains) losses reclassified into earnings, net of tax expense (benefit) of $104, $(37), and $0 for fiscal 2018, 2017, and 2016, respectively	(183)	50	1
Total- Available-for-sale investments	(737)	(39)	93
Cash flow hedging instruments:
Change in unrealized gains and losses, net of tax benefit (expense) of $(3), $(5), and $7 for fiscal 2018, 2017, and 2016, respectively	18	17	(59)
Net (gains) losses reclassified into earnings, net of tax (benefit) expense of $7, $(5), and $(4) for fiscal 2018, 2017, and 2016, respectively	(61)	74	16
Total- Cash flow hedging instruments	(43)	91	(43)
Net change in cumulative translation adjustment and actuarial gains and losses, net of tax benefit (expense) of $(8), $(13), and $(42) for fiscal 2018, 2017, and 2016, respectively	(160)	321	(447)
Other comprehensive income (loss)	(940)	373	(397)
Comprehensive income (loss)	(830)	9,982	10,342
Comprehensive (income) loss attributable to noncontrolling interests	0	(1)	10
Comprehensive income (loss) attributable to Cisco Systems, Inc.	$ (830)	$ 9,981	$ 10,352