Revenue and Accounts Receivable - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Investment Banking and Equities [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer	$ 2,721,793	$ 3,204,519	$ 2,238,156
Investment Banking and Equities [Member] | Advisory Fees [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer	2,392,990	2,751,992	1,755,273
Investment Banking and Equities [Member] | Underwriting Fees [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer	122,596	246,705	276,191
Investment Banking and Equities [Member] | Commissions and Related Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer	206,207	205,822	206,692
Investment Management [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer	64,483	65,784	54,397
Investment Management [Member] | Wealth Management [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer	64,483	65,784	53,069
Investment Management [Member] | Institutional Asset Management [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer	$ 0	$ 0	$ 1,328