Segment information - Reported Revenue and Profit Before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Revenue
Total revenue	$ 1,248,825	$ 1,110,941	$ 1,394,035
Pre-Tax Income (Loss)
Total pre-tax income (loss)	46,770	45,554	224,641
Corporate/Other
Revenue
Total revenue	12,741	(1,802)	(1,327)
Pre-Tax Income (Loss)
Total pre-tax income (loss)	$ (108,804)	$ (106,753)	$ (116,469)
Private Client
Pre-Tax Income (Loss)
Asset management fees	90.00%	90.00%	90.00%
Private Client | Operating Segments
Revenue
Total revenue	$ 801,754	$ 675,680	$ 665,060
Pre-Tax Income (Loss)
Total pre-tax income (loss)	$ 194,444	$ 142,250	$ 101,146
Asset Management
Pre-Tax Income (Loss)
Asset management fees	10.00%	10.00%	10.00%
Asset Management | Operating Segments
Revenue
Total revenue	$ 88,433	$ 99,242	$ 104,598
Pre-Tax Income (Loss)
Total pre-tax income (loss)	24,091	35,753	35,874
Capital markets | Operating Segments
Revenue
Total revenue	345,897	337,821	625,704
Pre-Tax Income (Loss)
Total pre-tax income (loss)	$ (62,961)	$ (25,696)	$ 204,090