Segment information - Schedule of Reported Revenue and Pre-Tax Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Revenue
Revenue	$ 330,589	$ 306,189	$ 683,727	$ 627,868
Pre-Tax Income (Loss)
Pre-Tax Income (Loss)	15,865	(11,699)	53,320	7,350
Corporate/Other
Revenue
Revenue	3,922	3,164	7,016	7,181
Pre-Tax Income (Loss)
Pre-Tax Income (Loss)	$ (26,591)	$ (24,975)	$ (58,219)	$ (51,386)
Private Client
Pre-Tax Income (Loss)
Asset management fees (as a percent)	90.00%	90.00%	90.00%	90.00%
Private Client | Operating Segments
Revenue
Revenue	$ 208,701	$ 201,245	$ 421,734	$ 404,666
Pre-Tax Income (Loss)
Pre-Tax Income (Loss)	$ 55,537	$ 20,794	$ 123,688	$ 75,250
Asset Management
Pre-Tax Income (Loss)
Asset management fees (as a percent)	10.00%	10.00%	10.00%	10.00%
Asset Management | Operating Segments
Revenue
Revenue	$ 25,825	$ 22,198	$ 50,753	$ 46,157
Pre-Tax Income (Loss)
Pre-Tax Income (Loss)	8,694	6,533	16,328	13,014
Capital markets | Operating Segments
Revenue
Revenue	92,141	79,582	204,224	169,864
Pre-Tax Income (Loss)
Pre-Tax Income (Loss)	$ (21,775)	$ (14,051)	$ (28,477)	$ (29,528)