Employee Benefit Plans - Summary of Impact of Deferred Plan (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2012
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Increase (reduction) to cost of revenue and operating expense	$ 10,856	$ 18,453	$ 7,498
Other income (expense), net	10,856us-gaap_OtherOperatingIncomeExpenseNet	18,453us-gaap_OtherOperatingIncomeExpenseNet	7,498us-gaap_OtherOperatingIncomeExpenseNet
Net increase (decrease) to net income	$ 0snps_NetIncreaseDecreaseToNetIncome	$ 0snps_NetIncreaseDecreaseToNetIncome	$ 0snps_NetIncreaseDecreaseToNetIncome

The compensation expense recognized during the period pertaining to the deferred compensation arrangement.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 710

-SubTopic 10

-Section 30

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6409875&loc=d3e20015-108363

Name:	us-gaap_DeferredCompensationArrangementWithIndividualCompensationExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration