Goodwill and Intangible Assets - Estimated Future Amortization of Intangible Assets, Additional Information (Detail)	6 Months Ended
Apr. 30, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Projects estimated to be completed (years)	1 year

Estimated completion period of in process research and development projects.

No definition available.

Name:	snps_EstimatedCompletionPeriodOfInProcessResearchAndDevelopmentProjects
Namespace Prefix:	snps_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration