v3.10.0.1

Derivative Instruments (Effect of Derivative Instruments Designated as Fair Value Hedges and Underlying Hedged Items on Consolidated Statements of Operations) (Details) - Derivatives Designated as Fair Value Hedging Instruments - USD ($) $ in Millions | 3 Months Ended
--- | ---
Oct. 27, 2018 | Oct. 28, 2017
Hedge Underlying Gain Loss [Line Items] |  |
GAINS (LOSSES) ON DERIVATIVE INSTRUMENTS | $ (9) | $ (60)
GAINS (LOSSES) RELATED TO HEDGED ITEMS | 9 | 60
Interest rate derivatives | Interest expense |  |
Hedge Underlying Gain Loss [Line Items] |  |
GAINS (LOSSES) ON DERIVATIVE INSTRUMENTS | (9) | (46)
GAINS (LOSSES) RELATED TO HEDGED ITEMS | 9 | 46
Equity derivatives | Other income (loss), net |  |
Hedge Underlying Gain Loss [Line Items] |  |
GAINS (LOSSES) ON DERIVATIVE INSTRUMENTS | 0 | (14)
GAINS (LOSSES) RELATED TO HEDGED ITEMS | $ 0 | $ 14

X
- Definition Hedge Underlying Gain Loss [Line Items] + References No definition available. + Details
Name: | csco_HedgeUnderlyingGainLossLineItems
Namespace Prefix: | csco_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of the increase (decrease) in fair value of the hedged item in a fair value hedge recognized in the income statement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 25 -Section 50 -Paragraph 1 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=109977999&loc=d3e76258-113986 + Details
Name: | us-gaap_ChangeInUnrealizedGainLossOnHedgedItemInFairValueHedge1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Total amount of gain (loss) derived from fair value hedges recognized in earnings in the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624171-113959 + Details
Name: | us-gaap_GainLossOnFairValueHedgesRecognizedInEarnings
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=us-gaap_FairValueHedgingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateContractMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_InterestExpenseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_EquityContractMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_OtherIncomeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |