Segment Reporting (Schedule Of Operating Information, Segment) (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020
Segment Reporting Information [Line Items]
Net revenues	[1]	$ 1,134,789	$ 913,034
Income/(loss) before income taxes		227,892	115,106
Global Wealth Management [Member]
Segment Reporting Information [Line Items]
Net revenues	[1]	631,495	582,956
Income/(loss) before income taxes		223,231	194,167
Institutional Group [Member]
Segment Reporting Information [Line Items]
Net revenues	[1]	506,081	332,238
Income/(loss) before income taxes		117,188	41,740
Other Segments [Member]
Segment Reporting Information [Line Items]
Net revenues	[1]	(2,787)	(2,160)
Income/(loss) before income taxes		$ (112,527)	$ (120,801)

[1] No individual client accounted for more than 10 percent of total net revenues for the three months ended March 31, 2021 or 2020.