Segment Information - Reported Revenue and Profit Before Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenue
Total revenue	$ (264,730)	$ (250,935)	$ (499,500)	$ (502,705)
Income (loss) before income taxes
Operating Income (Loss)	23,264	17,391	33,487	33,443
Private Client Division
Revenue
Total revenue	(141,825)	(161,928)	(283,243)	(325,455)
Income (loss) before income taxes
Income before income taxes	24,349	43,416	$ 57,718	86,250
Asset management fees			90.00%
Asset Management
Revenue
Total revenue	(17,515)	(18,622)	$ (36,791)	(35,208)
Income (loss) before income taxes
Income before income taxes	3,983	5,318	$ 8,288	7,560
Asset management fees			10.00%
Capital markets
Revenue
Total revenue	(105,270)	(71,819)	$ (180,812)	(142,780)
Income (loss) before income taxes
Income before income taxes	22,322	(1,801)	22,179	(4,448)
Corporate/Other
Revenue
Total revenue	(120)	1,434	1,346	738
Income (loss) before income taxes
Income before income taxes	$ (27,390)	$ (29,542)	$ (54,698)	$ (55,919)