Consolidated Statements Of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jan. 28, 2017	Jan. 23, 2016	Jan. 28, 2017	Jan. 23, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 2,348	$ 3,147	$ 4,670	$ 5,577
Available-for-sale investments:
Change in net unrealized gains, net of tax benefit (expense) of $73 and $154 for the three and six months ended January 28, 2017, respectively, and $149 and $205 for the corresponding periods of fiscal 2016, respectively	(276)	(212)	(397)	(312)
Net (gains) losses reclassified into earnings, net of tax (benefit) expense of $(11) and $(6) for the three and six months ended January 28, 2017, respectively, and $(7) for each of the three and six months ended January 23, 2016	19	12	9	13
Total- Available-for-sale investments	(257)	(200)	(388)	(299)
Cash flow hedging instruments:
Change in unrealized gains and losses, net of tax benefit (expense) of $1 and $4 for the three and six months ended January 28, 2017, respectively, and $1 and $4 for the corresponding periods of fiscal 2016, respectively	(1)	(19)	(44)	(20)
Net (gains) losses reclassified into earnings, net of tax (benefit) expense of $(2) and $(3) for the three and six months ended January 28, 2017, respectively, and $(1) and $(2) for the corresponding periods of fiscal 2016, respectively	25	4	36	6
Total- Cash flow hedging instruments	24	(15)	(8)	(14)
Net change in cumulative translation adjustment and actuarial gains and losses net of tax benefit (expense) of $0 and $(1) for the three and six months ended January 28, 2017, respectively, and $5 and $(34) for the corresponding periods of fiscal 2016, respectively	(44)	(341)	(71)	(557)
Other comprehensive income (loss)	(277)	(556)	(467)	(870)
Comprehensive income	2,071	2,591	4,203	4,707
Comprehensive (income) loss attributable to noncontrolling interests	0	1	(8)	2
Comprehensive income attributable to Cisco Systems, Inc.	$ 2,071	$ 2,592	$ 4,195	$ 4,709