Segment information - Reported Revenue and Profit Before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenue
Total revenue	$ 1,394,035	$ 1,198,667	$ 1,033,379
Income (loss) before income taxes
Pre-Tax Income (Loss)	224,641	169,000	74,912
Private Client
Revenue
Total revenue	665,060	642,083	653,409
Income (loss) before income taxes
Pre-Tax Income (Loss)	$ 101,146	$ 122,844	$ 163,917
Asset management fees	90.00%	90.00%	90.00%
Asset Management
Revenue
Total revenue	$ 104,598	$ 130,274	$ 88,755
Income (loss) before income taxes
Pre-Tax Income (Loss)	$ 35,874	$ 71,625	$ 31,606
Asset management fees	10.00%	10.00%	10.00%
Capital markets
Revenue
Total revenue	$ 625,704	$ 426,752	$ 290,830
Income (loss) before income taxes
Pre-Tax Income (Loss)	204,090	83,442	(13,724)
Corporate/Other
Revenue
Total revenue	(1,327)	(442)	385
Income (loss) before income taxes
Pre-Tax Income (Loss)	$ (116,469)	$ (108,911)	$ (106,887)