Revenues From Contracts With Customers (Revenues from Contracts with Customers Disaggregated by Major Business Activity and Primary Geographic Regions) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Disaggregation Of Revenue [Line Items]
Commissions	$ 710,589	$ 809,500
Investment banking	971,485	1,565,381
Revenue from contracts with customers	2,950,827	3,615,636
Capital Raising [Member]
Disaggregation Of Revenue [Line Items]
Investment banking	256,862	709,298	[1]
Advisory [Member]
Disaggregation Of Revenue [Line Items]
Investment banking	714,623	856,083	[1]
Asset Management [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers	1,262,919	1,206,516
Other [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers	5,834	34,239
Global Wealth Management [Member]
Disaggregation Of Revenue [Line Items]
Commissions	473,638	567,491
Investment banking	19,515	48,210
Revenue from contracts with customers	1,761,563	1,854,521
Global Wealth Management [Member] | Capital Raising [Member]
Disaggregation Of Revenue [Line Items]
Investment banking	19,515	48,210	[1]
Global Wealth Management [Member] | Asset Management [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers	1,262,841	1,206,406
Global Wealth Management [Member] | Other [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers	5,569	32,414
Institutional Group [Member]
Disaggregation Of Revenue [Line Items]
Commissions	236,951	242,009
Investment banking	951,970	1,517,171
Revenue from contracts with customers	1,188,999	1,759,290
Institutional Group [Member] | Capital Raising [Member]
Disaggregation Of Revenue [Line Items]
Investment banking	237,347	661,088	[1]
Institutional Group [Member] | Advisory [Member]
Disaggregation Of Revenue [Line Items]
Investment banking	714,623	856,083	[1]
Institutional Group [Member] | Asset Management [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers	78	110
Other [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers	265	1,825
Other [Member] | Other [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers	265	1,825
United States [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers	2,732,788	3,289,559
United States [Member] | Global Wealth Management [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers	1,761,563	1,854,521
United States [Member] | Institutional Group [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers	970,960	1,433,213
United States [Member] | Other [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers	265	1,825
United Kingdom [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers	148,690	188,984
United Kingdom [Member] | Institutional Group [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers	148,690	188,984
Canada [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers	33,718	93,068
Canada [Member] | Institutional Group [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers	33,718	93,068
Other [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers	35,631	44,025
Other [Member] | Institutional Group [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contracts with customers	$ 35,631	$ 44,025

[1] Excludes revenues not derived from contracts with customers in the Other segment.