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

Amount borrowed under the credit facility as of the balance sheet date.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

Name:	us-gaap_LineOfCreditFacilityAmountOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityCommitmentFeePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Description of the conditions for borrowing under the credit facility including the nature of any restrictions.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 129

-Paragraph 2, 4

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- Definition

Reflects when the credit facility terminates, which may be presented in a variety of ways (year, month and year, day, month and year, quarter).

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityExpirationDate
Namespace Prefix:	us-gaap_
Data Type:	us-types:dateStringItemType
Balance Type:	na
Period Type:	duration

- Definition

Increase for additional borrowings on the credit facility during the period.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 4

-Section 08

-Paragraph f

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(f))

-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690

+ Details

Name:	us-gaap_LineOfCreditFacilityIncreaseAdditionalBorrowings
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Reflects when the credit facility first became available, which may be presented in a variety of ways (year, month and year, day, month and year, quarter).

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityInitiationDate
Namespace Prefix:	us-gaap_
Data Type:	us-types:dateStringItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Credit Facility (Details) (USD $)	3 Months Ended
Credit Facility (Details) (USD $)	Jan. 31, 2012	Oct. 31, 2011	Feb. 17, 2012	Oct. 14, 2011
Credit Facility [Line Items]
Senior unsecured revolving credit facility entered date	February 17, 2012
Senior unsecured revolving credit facility financial covenants	The facility contains financial covenants requiring the Company to operate within a maximum leverage ratio and specified levels of cash, as well as other non-financial covenants.
Senior unsecured revolving credit facility termination date	October 14, 2016
Senior unsecured revolving credit facility additional borrowings	150,000,000
Outstanding borrowing under credit facility	0
Maximum [Member]
Credit Facility [Line Items]
Commitment fee percentage	0.30%
Minimum [Member]
Credit Facility [Line Items]
Commitment fee percentage	0.15%
$350 Million Senior Unresolved Revolving Credit [Member]
Credit Facility [Line Items]
Senior unsecured revolving credit facility entered date		October 14, 2011
Senior unsecured revolving credit facility maximum borrowing capacity			350,000,000	350,000,000
Senior unsecured revolving credit facility termination date	October 14, 2016
$300 Million Senior Unresolved Revolving Credit [Member]
Credit Facility [Line Items]
Senior unsecured revolving credit facility maximum borrowing capacity				$ 300,000,000
Senior unsecured revolving credit facility termination date		October 14, 2011