Segment Reporting (Schedule Of Operating Information, Segment) (Details) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Sep. 30, 2015 USD ($) item	Sep. 30, 2014 USD ($)
Segment Reporting Information [Line Items]
Number of business segments | item				3
Net revenues	[1]	$ 591,575	$ 523,455	$ 1,750,308	$ 1,630,348
Income before income tax expense		$ 22,348	$ 65,766	$ 130,485	$ 221,417
Net revenues accounted for by individual client, maximum percentage		10.00%	10.00%	10.00%	10.00%
Global Wealth Management [Member]
Segment Reporting Information [Line Items]
Number of businesses within reportable segment | item				2
Net revenues	[1]	$ 357,306	$ 317,241	$ 1,030,097	$ 921,671
Income before income tax expense		97,227	94,026	290,049	262,800
Institutional Group [Member]
Segment Reporting Information [Line Items]
Net revenues	[1]	232,125	215,160	729,269	720,849
Income before income tax expense		25,853	29,500	100,124	117,812
Other [Member]
Segment Reporting Information [Line Items]
Net revenues	[1]	2,144	(8,946)	(9,058)	(12,172)
Income before income tax expense		$ (100,732)	$ (57,760)	$ (259,688)	$ (159,195)

[1] No individual client accounted for more than 10 percent of total net revenues for the three and nine months ended September 30, 2015 or 2014.