Revenue and Accounts Receivable - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Investment Banking and Equities [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer	$ 652,429	$ 462,804	$ 1,186,040	$ 996,314
Investment Banking and Equities [Member] | Advisory Fees [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer	568,231	374,556	998,069	837,118
Investment Banking and Equities [Member] | Underwriting Fees [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer	30,999	38,200	86,534	61,083
Investment Banking and Equities [Member] | Commissions and Related Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer	53,199	50,048	101,437	98,113
Investment Management [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer	19,200	16,575	37,899	32,533
Investment Management [Member] | Wealth Management [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer	$ 19,200	$ 16,575	$ 37,899	$ 32,533