Estimated Future Amortization of Intangible Assets (Parenthetical) (Detail)	Jan. 31, 2014 Y
Expected Amortization Expense [Line Items]
Projects estimated to be completed	1

Estimated completion period of in process research and development projects.

No definition available.

Name:	snps_EstimatedCompletionPeriodOfInProcessResearchAndDevelopmentProjects
Namespace Prefix:	snps_
Data Type:	xbrli:positiveIntegerItemType
Balance Type:	na
Period Type:	instant