Acquisitions - Narrative (Details) $ in Thousands		3 Months Ended		9 Months Ended		12 Months Ended
	Jun. 17, 2021 USD ($) shares	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2021 USD ($) acquisition	Sep. 30, 2020 USD ($)	Dec. 31, 2020 USD ($) acquisition
Business Combination, Separately Recognized Transactions [Line Items]
Net cash paid				$ 1,033,695	$ 68,920
Fair value adjustments reducing revenue		$ (248,480)	$ (202,997)	(693,416)	(581,977)
Series of Individually Immaterial Business Acquisitions
Business Combination, Separately Recognized Transactions [Line Items]
Total consideration				1,269,584		$ 102,094
Net cash paid				$ 1,033,695		$ 93,032
Number of acquisitions | acquisition				12		6
Acquisition and integration costs		943	531	$ 18,037	1,609
Goodwill from acquisition, expected tax deductible amount		16,244		16,244
Series of Individually Immaterial Business Acquisitions | Acquired Support Contracts Adjustment To Revenue
Business Combination, Separately Recognized Transactions [Line Items]
Fair value adjustments reducing revenue		2,914	288	3,924	483
Seequent
Business Combination, Separately Recognized Transactions [Line Items]
Net cash paid	$ 910,997
Acquisition and integration costs		389		16,285
Business acquisition, pro forma revenue		$ 248,480	$ 220,828	$ 746,025	$ 640,008
Seequent | Class B Common Stock
Business Combination, Separately Recognized Transactions [Line Items]
Number of shares sold (in shares) | shares	3,141,342