Financial Assets and Liabilities - Additional Information (Details)	6 Months Ended
Apr. 30, 2015
Financial Assets and Liabilities [Line Items]
Shipments period using hedges (in months)	one
Period for hedge balance in OCI to be reclassified to statement of operations (in months)	12 months
Foreign Exchange Contracts \| Maximum
Financial Assets and Liabilities [Line Items]
Duration of foreign exchange forward contracts	1 year
Cash Flow Hedging \| Foreign Exchange Forward contracts \| Maximum
Financial Assets and Liabilities [Line Items]
Derivative maturity period	22 months
Foreign currency derivative contracts \| Minimum
Financial Assets and Liabilities [Line Items]
Derivative maturity period	1 month
Foreign currency derivative contracts \| Maximum
Financial Assets and Liabilities [Line Items]
Derivative maturity period	22 months
Foreign currency derivative contracts \| Cash Flow Hedging \| Maximum
Financial Assets and Liabilities [Line Items]
Derivative maturity period	3 years
Non-Designated Hedging Instrument
Financial Assets and Liabilities [Line Items]
Forward contracts terms (in months)	1 month

Name:	snps_FinancialAssetsAndLiabilitiesLineItems
Namespace Prefix:	snps_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

High end period remaining until maturity for the derivative contract, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeHigherRemainingMaturityRange1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Estimated period for the anticipated transfer of gain (loss), net, from accumulated other comprehensive income into earnings, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeInstrumentsGainLossReclassificationFromAccumulatedOCIToIncomeEstimateOfTimeToTransfer1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Period the derivative contract is outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeTermOfContract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Description of the reasons for holding or issuing foreign currency exchange rate derivative instruments. Includes discussion of the objectives for holding the instruments, the context needed to understand those objectives, and the strategies for achieving those objectives. Disclosures may be more meaningful if such objectives and strategies are described in the context of an entity's overall risk management profile.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1A

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5579245-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5579240-113959

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=35706170&loc=d3e41641-113959

+ Details

Name:	us-gaap_DiscussionOfObjectivesForUsingForeignCurrencyDerivativeInstruments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum period of time the entity is hedging its exposure to variability in future cash flows for forecasted transactions, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Excludes forecasted transactions related to payment of variable interest on existing financial instruments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=35736893&loc=d3e80748-113994

+ Details

Name:	us-gaap_MaximumLengthOfTimeForeignCurrencyCashFlowHedge
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_DerivativeByNatureAxis=us-gaap_ForwardContractsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_ForeignExchangeContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=us-gaap_CashFlowHedgingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_HedgingDesignationAxis=us-gaap_NondesignatedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: