Segment information - Reported Revenue and Profit Before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Segment Reporting Information [Line Items]
Total revenue	$ 1,432,496	$ 1,248,825	$ 1,110,941
Compensation Expenses	936,813	782,396	740,827
Other Segment Items	389,926	419,659	324,560
Income (loss) before income taxes from continuing operations	105,757	46,770	45,554
Corporate/Other
Segment Reporting Information [Line Items]
Total revenue	12,865	12,741	(1,802)
Compensation Expenses	98,974	89,035	77,921
Other Segment Items	34,277	32,510	27,030
Income (loss) before income taxes from continuing operations	(120,386)	(108,804)	(106,753)
Wealth Management Segment | Operating Segments
Segment Reporting Information [Line Items]
Total revenue	972,052	890,187	774,922
Compensation Expenses	514,227	424,031	401,932
Other Segment Items	192,086	247,621	194,987
Income (loss) before income taxes from continuing operations	265,739	218,535	178,003
Capital Markets | Operating Segments
Segment Reporting Information [Line Items]
Total revenue	447,579	345,897	337,821
Compensation Expenses	323,612	269,330	260,974
Other Segment Items	163,563	139,528	102,543
Income (loss) before income taxes from continuing operations	$ (39,596)	$ (62,961)	$ (25,696)