Goodwill and Identifiable Intangible Assets - Change in Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Goodwill [Roll Forward]
Beginning balance		$ 3,545,297	$ 3,512,567
Goodwill from acquisitions		9,616	12,341
Net cash payments relating to prior acquisitions			2,009
Net increase relating to measurement period adjustments		832	18,380
Goodwill impairment	$ 318,900	830,787	0	$ 0
Ending balance	$ 2,724,958	$ 2,724,958	$ 3,545,297	$ 3,512,567