v2.4.0.6

Summary of Intangible Assets (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Oct. 31, 2012
Finite-Lived Intangible Assets [Line Items]
Acquisition of additional intangible assets	$ 370.7

X

- Definition

Acquisition of additional intangible assets.

+ References

No definition available.

+ Details

Name:	snps_AcquisitionOfAdditionalIntangibleAssets
Namespace Prefix:	snps_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Details

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