Revenue (Details)	3 Months Ended			6 Months Ended
	Jun. 29, 2019		Jun. 30, 2018	Jun. 29, 2019		Jun. 30, 2018
Revenue from External Customer [Line Items]
Percentage of product and maintenance revenue by product group	100.00%		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	22.00%	[1]	23.00%	23.00%	[1]	25.00%
Digital IC Design and Signoff [Member]
Revenue from External Customer [Line Items]
Percentage of product and maintenance revenue by product group	31.00%		30.00%	31.00%		29.00%
Custom IC Design and Simulation [Member]
Revenue from External Customer [Line Items]
Percentage of product and maintenance revenue by product group	26.00%		26.00%	26.00%		26.00%
System Interconnect and Analysis [Member]
Revenue from External Customer [Line Items]
Percentage of product and maintenance revenue by product group	10.00%		9.00%	9.00%		9.00%
IP [Member]
Revenue from External Customer [Line Items]
Percentage of product and maintenance revenue by product group	11.00%		12.00%	11.00%		11.00%

[1] Includes immaterial amount of revenue accounted for under Topic 842.