Acquisitions - Valuation Assumptions and Weighted-Average Useful Life (Details)				12 Months Ended
	Dec. 01, 2020	Apr. 01, 2020	May 02, 2018	Dec. 31, 2020	Nov. 01, 2019	Feb. 01, 2019
Developed Software and Core Technologies
Finite-lived intangible asset, useful life				10 years
Trade Names
Finite-lived intangible asset, useful life				10 years
Customer Lists
Finite-lived intangible asset, useful life				15 years
Analytical Graphics, Inc. | Developed Software and Core Technologies
Finite-lived intangible asset, useful life	10 years
Royalty Rate	40.00%
Discount Rate	11.00%
Analytical Graphics, Inc. | Trade Names
Finite-lived intangible asset, useful life	9 years
Discount Rate	11.00%
Analytical Graphics, Inc. | Customer Lists
Finite-lived intangible asset, useful life	15 years
Discount Rate	12.00%
Attrition Rate	10.00%
Analytical Graphics, Inc. | Minimum | Trade Names
Royalty Rate	1.00%
Analytical Graphics, Inc. | Maximum | Trade Names
Royalty Rate	2.00%
Lumerical | Developed Software and Core Technologies
Finite-lived intangible asset, useful life		10 years
Discount Rate		16.50%
Lumerical | Trade Names
Finite-lived intangible asset, useful life		6 years
Royalty Rate		2.00%
Discount Rate		16.50%
Lumerical | Customer Lists
Finite-lived intangible asset, useful life		10 years
Discount Rate		12.50%
Attrition Rate		10.00%
Livermore Software Technology Corporation | Developed Software and Core Technologies
Royalty Rate					50.00%
Discount Rate					10.00%
Livermore Software Technology Corporation | Trade Names
Royalty Rate					2.00%
Discount Rate					10.00%
Livermore Software Technology Corporation | Customer Lists
Discount Rate					11.00%
Attrition Rate					10.00%
Granta Design | Developed Software and Core Technologies
Discount Rate						12.50%
Granta Design | Trade Names
Royalty Rate						2.00%
Discount Rate						14.00%
Granta Design | Customer Lists
Discount Rate						12.50%
Attrition Rate						10.00%
Granta Design | Minimum | Developed Software and Core Technologies
Royalty Rate						8.00%
Granta Design | Maximum | Developed Software and Core Technologies
Royalty Rate						10.00%
OPTIS | Developed Software and Core Technologies
Finite-lived intangible asset, useful life			10 years
OPTIS | Trade Names
Finite-lived intangible asset, useful life			9 years
OPTIS | Customer Lists
Finite-lived intangible asset, useful life			12 years