Segment Reporting (Schedule Of Operating Information, Segment) (Details) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) item	Jun. 30, 2014 USD ($)
Segment Reporting Information [Line Items]
Number of business segments | item				3
Net revenues	[1]	$ 597,751	$ 560,105	$ 1,158,733	$ 1,106,862
Income before income tax expense		$ 38,071	$ 74,419	$ 108,137	$ 151,849
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]	$ 343,382	$ 307,247	$ 672,792	$ 604,430
Income before income tax expense		93,975	89,098	192,823	168,774
Institutional Group [Member]
Segment Reporting Information [Line Items]
Net revenues	[1]	258,538	255,670	497,145	505,647
Income before income tax expense		41,942	42,312	74,273	87,222
Other [Member]
Segment Reporting Information [Line Items]
Net revenues	[1]	(4,169)	(2,812)	(11,204)	(3,215)
Income before income tax expense		$ (97,846)	$ (56,991)	$ (158,959)	$ (104,147)

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