Segment Information - Reported Revenue and Profit Before Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenue
Total revenue	$ (250,935)	$ (242,556)	$ (502,705)	$ (477,086)
Income (loss) before income taxes
Operating Income (Loss)	17,391	12,517	33,443	22,138
Private Client Division
Revenue
Total revenue	(161,928)	(156,553)	(325,455)	(310,647)
Income (loss) before income taxes
Income before income taxes	$ 43,416	33,513	86,250	73,675
Asset management fees	90.00%
Asset Management
Revenue
Total revenue	$ (18,622)	(17,706)	(35,208)	(35,350)
Income (loss) before income taxes
Income before income taxes	$ 5,318	3,958	7,560	7,676
Asset management fees	10.00%
Capital markets
Revenue
Total revenue	$ (71,819)	(68,206)	(142,780)	(129,735)
Income (loss) before income taxes
Income before income taxes	(1,801)	(199)	(4,448)	(6,256)
Corporate/Other
Revenue
Total revenue	1,434	(91)	738	(1,354)
Income (loss) before income taxes
Income before income taxes	$ (29,542)	$ (24,755)	$ (55,919)	$ (52,957)