Subsidiaries Remain Subject to Tax Examination (Detail)	12 Months Ended
	Oct. 31, 2012
United States - Synopsys
Income Tax Examination [Line Items]
Year(s) Subject to Examination	Fiscal 2012
United States - Magma Design Automation
Income Tax Examination [Line Items]
Year(s) Subject to Examination	Fiscal years after 2008
California - Synopsys
Income Tax Examination [Line Items]
Year(s) Subject to Examination	Fiscal years after 2007
California - Magma Design Automation
Income Tax Examination [Line Items]
Year(s) Subject to Examination	Fiscal years after 2007
Hungary
Income Tax Examination [Line Items]
Year(s) Subject to Examination	Fiscal years after 2005
Taiwan and Japan
Income Tax Examination [Line Items]
Year(s) Subject to Examination	Fiscal years after 2006
Ireland
Income Tax Examination [Line Items]
Year(s) Subject to Examination	Fiscal years after 2007