Comprehensive Income (Loss) (AOCI components) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Apr. 27, 2019	Apr. 28, 2018	Apr. 27, 2019	Apr. 28, 2018
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, beginning of period			$ 43,204
Other comprehensive income (loss)	$ 214	$ (732)	121	$ (695)
Balance, end of period	36,804		36,804
Net Unrealized Gains (Losses) on Available-for-Sale Investments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, beginning of period			(310)	373
Other comprehensive income (loss) before reclassifications attributable to Cisco Systems, Inc.			382	(620)
(Gains) losses reclassified out of AOCI			18	(108)
Tax benefit (expense)			(59)	24
Other comprehensive income (loss)			341	(704)
Effect of adoption of accounting standards	(168)	54	(168)	54
Balance, end of period	(137)	(277)	(137)	(277)
Net Unrealized Gains (Losses) Cash Flow Hedging Instruments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, beginning of period			(11)	32
Other comprehensive income (loss) before reclassifications attributable to Cisco Systems, Inc.			3	28
(Gains) losses reclassified out of AOCI			(1)	(59)
Tax benefit (expense)			0	4
Other comprehensive income (loss)			2	(27)
Effect of adoption of accounting standards	0	0	0	0
Balance, end of period	(9)	5	(9)	5
Cumulative Translation Adjustment and Actuarial Gains (Losses)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, beginning of period			(528)	(359)
Other comprehensive income (loss) before reclassifications attributable to Cisco Systems, Inc.			(224)	34
(Gains) losses reclassified out of AOCI			4	5
Tax benefit (expense)			(2)	(3)
Other comprehensive income (loss)			(222)	36
Effect of adoption of accounting standards	0	(9)	0	(9)
Balance, end of period	(750)	(332)	(750)	(332)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, beginning of period			(849)	46
Other comprehensive income (loss) before reclassifications attributable to Cisco Systems, Inc.			161	(558)
(Gains) losses reclassified out of AOCI			21	(162)
Tax benefit (expense)			(61)	25
Other comprehensive income (loss)	214	(732)	121	(695)
Effect of adoption of accounting standards	(168)	45	(168)	45
Balance, end of period	$ (896)	$ (604)	$ (896)	$ (604)

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount after tax of increase (decrease) to equity or (increase) decrease to net assets, resulting from the cumulative effect adjustment of a new accounting principle applied in the period of adoption.

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Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

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