Acquisitions - Recognized Amounts of Identifiable Assets Acquired and Liabilities Assumed 2020 (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 01, 2020	Apr. 01, 2020
Cash	$ 16,673	$ 29,507
Accounts receivable and other tangible assets	10,047	32,921
Accounts payable and other liabilities	(7,609)	(24,724)
Deferred revenue	(3,831)	(6,872)
Net deferred tax liabilities	(32,118)	(59,925)
Total identifiable net assets	131,662	233,593
Goodwill	390,548	594,041
Developed Software and Core Technologies
Finite-lived intangible assets	128,200	215,714
Customer Lists
Finite-lived intangible assets	12,300	27,016
Trade Names
Finite-lived intangible assets	$ 8,000	$ 19,956
Analytical Graphics, Inc.
Cash			$ 17,663
Accounts receivable and other tangible assets			28,677
Accounts payable and other liabilities			(23,576)
Deferred revenue			(5,467)
Net deferred tax liabilities			(52,473)
Total identifiable net assets			192,524
Goodwill			527,565
Analytical Graphics, Inc. | Developed Software and Core Technologies
Finite-lived intangible assets			184,100
Analytical Graphics, Inc. | Customer Lists
Finite-lived intangible assets			25,400
Analytical Graphics, Inc. | Trade Names
Finite-lived intangible assets			$ 18,200
Lumerical
Cash				$ 11,844
Accounts receivable and other tangible assets				4,244
Accounts payable and other liabilities				(1,148)
Deferred revenue				(1,405)
Net deferred tax liabilities				(7,452)
Total identifiable net assets				41,069
Goodwill				66,476
Lumerical | Developed Software and Core Technologies
Finite-lived intangible assets				31,614
Lumerical | Customer Lists
Finite-lived intangible assets				1,616
Lumerical | Trade Names
Finite-lived intangible assets				$ 1,756