Revenue and Accounts Receivable - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Investment Banking and Equities [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer	$ 2,277,662	$ 2,721,793	$ 3,204,519
Investment Banking and Equities [Member] | Advisory Fees [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer	1,963,857	2,392,990	2,751,992
Investment Banking and Equities [Member] | Underwriting Fees [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer	111,016	122,596	246,705
Investment Banking and Equities [Member] | Commissions and Related Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer	202,789	206,207	205,822
Investment Management [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer	67,041	64,483	65,784
Investment Management [Member] | Wealth Management [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer	$ 67,041	$ 64,483	$ 65,784