Segment Operating Results (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Segment Reporting Information [Line Items]
Net Revenues	$ 572,143	$ 722,854
Operating Expenses	462,318	513,490
Other Expenses	2,921	0
Income Before Income from Equity Method Investments and Income Taxes	106,904	209,364
Income from Equity Method Investments	1,468	2,512
Pre-Tax Income	108,372	211,876
Identifiable Segment Assets	2,750,472	2,938,364	$ 3,620,923
Investment Banking and Equities [Member]
Segment Reporting Information [Line Items]
Net Revenues	554,811	704,301
Operating Expenses	449,080	500,572
Other Expenses	2,921	0
Income Before Income from Equity Method Investments and Income Taxes	102,810	203,729
Income from Equity Method Investments	71	374
Pre-Tax Income	102,881	204,103
Identifiable Segment Assets	2,608,350	2,787,619
Investment Management [Member]
Segment Reporting Information [Line Items]
Net Revenues	17,332	18,553
Operating Expenses	13,238	12,918
Income Before Income from Equity Method Investments and Income Taxes	4,094	5,635
Income from Equity Method Investments	1,397	2,138
Pre-Tax Income	5,491	7,773
Identifiable Segment Assets	$ 142,122	$ 150,745