Goodwill and other intangibles - Summary of Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Goodwill summary
Beginning balances	$ 1,072,982	$ 924,837
Acquisitions	20,271	134,225
Purchase accounting adjustments	(20,977)	15,212
Disposals	(147)	(1,292)
Ending balances	1,072,129	1,072,982
Corporate and Other
Goodwill summary
Beginning balances	0	15,350
Acquisitions	0	0
Purchase accounting adjustments	0	(14,450)
Disposals	0	(900)
Ending balances	0	0
Title | Operating Segments
Goodwill summary
Beginning balances	720,478	583,944
Acquisitions	8,581	134,225
Purchase accounting adjustments	(20,977)	2,701
Disposals	(147)	(392)
Ending balances	707,935	720,478
Real Estate Solutions | Operating Segments
Goodwill summary
Beginning balances	352,504	325,543
Acquisitions	11,690	0
Purchase accounting adjustments	0	26,961
Disposals	0	0
Ending balances	$ 364,194	$ 352,504