Document and Entity Information - USD ($)	12 Months Ended
	Jan. 02, 2016	Feb. 06, 2016	Jul. 04, 2015
Document and Entity Information [Abstract]
Entity Registrant Name	CADENCE DESIGN SYSTEMS INC
Entity Central Index Key	0000813672
Document Type	10-K
Document Period End Date	Jan. 02, 2016
Amendment Flag	false
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--01-02
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 5,641,117,000
Entity Common Stock, Shares Outstanding		305,358,000