Income Taxes - Subsidiaries Remain Subject to Tax Examination (Detail)	12 Months Ended
	Oct. 31, 2015
United States - Synopsys
Income Tax Examination [Line Items]
Year(s) Subject to Examination	Fiscal 2015
United States - Magma Design Automation
Income Tax Examination [Line Items]
Year(s) Subject to Examination	Fiscal 2012
California - Synopsys
Income Tax Examination [Line Items]
Year(s) Subject to Examination	Fiscal years after 2010
California - Magma Design Automation
Income Tax Examination [Line Items]
Year(s) Subject to Examination	Fiscal years after 2010
Hungary
Income Tax Examination [Line Items]
Year(s) Subject to Examination	Fiscal years after 2008
Ireland, Japan, and Taiwan
Income Tax Examination [Line Items]
Year(s) Subject to Examination	Fiscal years after 2009