v2.4.0.6

Subsequent Events (Details) (Magma [Member], USD $) In Millions, except Per Share data, unless otherwise specified	Oct. 31, 2011
Magma [Member]
Subsequent Event [Line Items]
Percentage of common stock acquired	100.00%
Purchase price per share	$ 7.35
Total approximate purchase price	$ 507.0

X

- Definition

Business Acquisition, Cost Of Acquired Entity, Purchase Price Per Share, Total

+ References

No definition available.

+ Details

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Namespace Prefix:	snps_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

X

- Definition

The total cost of the acquired entity including the cash paid to shareholders of acquired entities, fair value of debt and equity securities issued to shareholders of acquired entities, the fair value of the liabilities assumed, and direct costs of the acquisition.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141

-Paragraph 51

-Subparagraph d

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Percentage of voting equity interests acquired in the business combination.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141R

-Paragraph 68

-Subparagraph c

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6909870&loc=d3e1392-128463

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Details

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Period Type:	duration