Segment Reporting (Schedule Of Operating Information, Segment) (Details) $ in Thousands		3 Months Ended
		Mar. 31, 2016 USD ($) item	Mar. 31, 2015 USD ($)
Segment Reporting Information [Line Items]
Number of business segments | item		3
Net revenues	[1]	$ 619,974	$ 560,982
Income before income tax expense		$ 43,913	$ 70,066
Net revenues accounted for by individual client, maximum percentage		10.00%	10.00%
Global Wealth Management [Member]
Segment Reporting Information [Line Items]
Number of businesses within reportable segment | item		2
Net revenues	[1]	$ 379,805	$ 329,410
Income before income tax expense		93,335	98,847
Institutional Group [Member]
Segment Reporting Information [Line Items]
Net revenues	[1]	241,276	238,607
Income before income tax expense		29,194	32,331
Other [Member]
Segment Reporting Information [Line Items]
Net revenues	[1]	(1,107)	(7,035)
Income before income tax expense		$ (78,616)	$ (61,112)

[1] No individual client accounted for more than 10 percent of total net revenues for the three months ended March 31, 2016 or 2015.