Segment Reporting (Schedule Of Operating Information, Segment) (Details) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($) item	Jun. 30, 2015 USD ($)
Segment Reporting Information [Line Items]
Number of business segments | item				3
Net revenues	[1]	$ 652,145	$ 597,751	$ 1,272,119	$ 1,158,733
Income before income tax expense		$ 15,794	$ 38,071	$ 59,706	$ 108,137
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]	$ 386,039	$ 343,382	$ 765,843	$ 672,792
Income before income tax expense		105,053	93,975	198,387	192,823
Institutional Group [Member]
Segment Reporting Information [Line Items]
Net revenues	[1]	260,920	258,538	502,196	497,145
Income before income tax expense		42,083	41,942	71,372	74,273
Other [Member]
Segment Reporting Information [Line Items]
Net revenues	[1]	5,186	(4,169)	4,080	(11,204)
Income before income tax expense		$ (131,342)	$ (97,846)	$ (210,053)	$ (158,959)

[1] No individual client accounted for more than 10 percent of total net revenues for the three and six months ended June 30, 2016 or 2015.