Revenue and Accounts Receivable - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Investment Banking and Equities [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer	$ 533,510	$ 711,768
Investment Banking and Equities [Member] | Advisory Fees [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer	462,562	624,564
Investment Banking and Equities [Member] | Underwriting Fees [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer	22,883	36,306
Investment Banking and Equities [Member] | Commissions and Related Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer	48,065	50,898
Investment Management [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer	15,958	17,115
Investment Management [Member] | Wealth Management [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer	$ 15,958	$ 17,115