Revenue (Details)	12 Months Ended
	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Revenue from External Customer [Line Items]
Percentage of Product and Maintenance Revenue by Product Group	100.00%	100.00%	100.00%
Functional Verification, including Emulation and Prototyping Hardware [Member]
Revenue from External Customer [Line Items]
Percentage of Product and Maintenance Revenue by Product Group	24.00%	22.00%	25.00%
Digital IC Design and Signoff [Member]
Revenue from External Customer [Line Items]
Percentage of Product and Maintenance Revenue by Product Group	29.00%	29.00%	29.00%
Custom IC Design [Member]
Revenue from External Customer [Line Items]
Percentage of Product and Maintenance Revenue by Product Group	26.00%	27.00%	25.00%
System Interconnect and Analysis [Member]
Revenue from External Customer [Line Items]
Percentage of Product and Maintenance Revenue by Product Group	9.00%	10.00%	10.00%
IP [Member]
Revenue from External Customer [Line Items]
Percentage of Product and Maintenance Revenue by Product Group	12.00%	12.00%	11.00%