Consolidated Statements Of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Oct. 29, 2016	Oct. 24, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 2,322	$ 2,430
Available-for-sale investments:
Change in net unrealized gains, net of tax benefit (expense) of $81 and $56 for the three months ended October 29, 2016 and October 24, 2015, respectively	(121)	(100)
Net (gains) losses reclassified into earnings, net of tax (benefit) expense of $5 and $0 for the three months ended October 29, 2016 and October 24, 2015, respectively	(10)	1
Total- Available-for-sale investments	(131)	(99)
Cash flow hedging instruments:
Change in unrealized gains and losses, net of tax benefit (expense) of $3 for each of the three months ended October 29, 2016 and October 24, 2015, respectively	(43)	(1)
Net (gains) losses reclassified into earnings, net of tax (benefit) expense of $(1) for each of the three months ended October 29, 2016 and October 24, 2015, respectively	11	2
Total- Cash flow hedging instruments	(32)	1
Net change in cumulative translation adjustment and actuarial gains and losses net of tax benefit (expense) of $(1) and $(39) for the three months ended October 29, 2016, and October 24, 2015, respectively	(27)	(216)
Other comprehensive income (loss)	(190)	(314)
Comprehensive income	2,132	2,116
Comprehensive (income) loss attributable to noncontrolling interests	(8)	1
Comprehensive income attributable to Cisco Systems, Inc.	$ 2,124	$ 2,117