Segment Operating Results (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Net Revenues	$ 2,762,048	$ 3,289,499	$ 2,263,905
Operating Expenses	2,062,880	2,178,500	1,688,015
Other Expenses	3,126	8,561	49,457
Income Before Income from Equity Method Investments and Income Taxes	696,042	1,102,438	526,433
Income from Equity Method Investments	7,999	14,161	14,398
Pre-Tax Income	704,041	1,116,599	540,831
Identifiable Segment Assets	3,620,923	3,802,657	3,370,888
Investment Banking and Equities [Member]
Segment Reporting Information [Line Items]
Net Revenues	2,696,125	3,223,889	2,217,386
Operating Expenses	2,009,913	2,125,871	1,637,542
Other Expenses	3,126	7	49,112
Income Before Income from Equity Method Investments and Income Taxes	683,086	1,098,011	530,732
Income from Equity Method Investments	1,217	1,337	1,546
Pre-Tax Income	684,303	1,099,348	532,278
Identifiable Segment Assets	3,446,075	3,605,332	3,186,864
Investment Management [Member]
Segment Reporting Information [Line Items]
Net Revenues	65,923	65,610	46,519
Operating Expenses	52,967	52,629	50,473
Other Expenses	0	8,554	345
Income Before Income from Equity Method Investments and Income Taxes	12,956	4,427	(4,299)
Income from Equity Method Investments	6,782	12,824	12,852
Pre-Tax Income	19,738	17,251	8,553
Identifiable Segment Assets	$ 174,848	$ 197,325	$ 184,024