Segment Reporting (Schedule Of Operating Information, Segment) (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Information [Line Items]
Net revenues	[1]	$ 750,358	$ 675,531
Income/(loss) before income taxes		119,554	79,019
Global Wealth Management [Member]
Segment Reporting Information [Line Items]
Net revenues	[1]	485,575	442,732
Income/(loss) before income taxes		176,771	142,052
Institutional Group [Member]
Segment Reporting Information [Line Items]
Net revenues	[1]	270,078	237,467
Income/(loss) before income taxes		44,570	39,872
Other [Member]
Segment Reporting Information [Line Items]
Net revenues	[1]	(5,295)	(4,668)
Income/(loss) before income taxes		$ (101,787)	$ (102,905)

[1] No individual client accounted for more than 10 percent of total net revenues for the three months ended March 31, 2018 or 2017.