Leases (Details Textual) $ in Thousands	Jan. 02, 2021 USD ($)
Leases [Abstract]
Operating lease obligations, leasing arrangements to commence in a future period	$ 5,900

Operating lease obligations related to leases commencing at a future date.

No definition available.

Name:	cdns_LeaseObligationsToCommenceInTheNextFiscalQuarter
Namespace Prefix:	cdns_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant