Acquisitions - Other Information (Details) - USD ($) $ in Thousands					3 Months Ended
	Jan. 03, 2022	Oct. 01, 2021	Jun. 07, 2021	Mar. 02, 2021	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Business Combinations
Goodwill arising in the acquisition					$ 704,788		$ 703,371
Revenue					81,551	$ 66,718
Net income					$ 2,210	$ 1,052
Author! B.V.
Business Combinations
Business consideration transferred				$ 2,667
Goodwill arising in the acquisition				1,200
Insight Medical Writing Limited
Business Combinations
Business consideration transferred			$ 15,197
Finite-lived intangible assets acquired			7,400
Goodwill arising in the acquisition			$ 4,700
Pinnacle 21, LLC
Business Combinations
Business consideration transferred		$ 339,075
Goodwill arising in the acquisition		$ 180,947
Equity acquired (as percentage)		100.00%
Discount for lack of mobility (as percentage)		7.00%
Integrated Nonclinical Development Solutions, Inc.
Business Combinations
Business consideration transferred	$ 8,148
Goodwill arising in the acquisition	2,855
Customer relationships | Author! B.V.
Business Combinations
Finite-lived intangible assets acquired				1,200
Customer relationships | Integrated Nonclinical Development Solutions, Inc.
Business Combinations
Finite-lived intangible assets acquired	2,500
Non-compete agreements | Author! B.V.
Business Combinations
Finite-lived intangible assets acquired				$ 100
Acquired software | Integrated Nonclinical Development Solutions, Inc.
Business Combinations
Finite-lived intangible assets acquired	$ 860