Segment Reporting (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Oct. 01, 2016	Oct. 03, 2015	Oct. 01, 2016	Oct. 03, 2015
Entity Wide Disclosure on Geographic Areas Revenue from External Customers
Total revenue	$ 446,220	$ 433,763	$ 1,347,103	$ 1,261,012
Americas:
Total Americas	204,639	206,313	637,514	598,535
United States [Member]
Entity Wide Disclosure on Geographic Areas Revenue from External Customers
Geographic Areas, revenue from External Customers	197,715	199,628	614,153	579,011
Other Americas [Member]
Entity Wide Disclosure on Geographic Areas Revenue from External Customers
Geographic Areas, revenue from External Customers	6,924	6,685	23,361	19,524
Asia [Member]
Entity Wide Disclosure on Geographic Areas Revenue from External Customers
Geographic Areas, revenue from External Customers	120,206	106,627	330,417	301,835
EMEA [Member]
Entity Wide Disclosure on Geographic Areas Revenue from External Customers
Geographic Areas, revenue from External Customers	83,124	80,193	257,308	240,777
Japan [Member]
Entity Wide Disclosure on Geographic Areas Revenue from External Customers
Geographic Areas, revenue from External Customers	$ 38,251	$ 40,630	$ 121,864	$ 119,865

Entity wide disclosure on geographic areas revenue from external customers attributed to country of domicile and other foreign countries.

No definition available.

+ Details

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Namespace Prefix:	cdns_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Entity wide disclosure on geographic areas revenue from external customers attributed to entity's country of domicile and other foreign countries.

+ References

No definition available.

+ Details

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- References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
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- Definition

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

+ Details

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- Definition

Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

+ References

+ Details

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- Details

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- Details

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- Details

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