Acquisitions and Acquisition-Related Contingent Consideration (Details 1) (USD $) In Millions, unless otherwise specified	12 Months Ended
Jan. 03, 2015
Business Acquisition, Contingent Consideration [Line Items]
Maximum potential cash payment to be paid	$ 10.0
Period over which contingent consideration may be paid	15 months
Maximum potential expense in future periods	$ 8.0

Business combination asset purchase contingent consideration maximum potential expense in future period.

No definition available.

Name:	cdns_BusinessCombinationAssetPurchaseContingentConsiderationMaximumPotentialExpenseInFuturePeriod
Namespace Prefix:	cdns_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration