Segment Reporting (Schedule Of Operating Information, Segment) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Number of business segments			3
Number of businesses within reportable segment			2
Net revenues	$ 374,407	$ 358,857	$ 774,740	$ 725,470
Income before income tax expense	43,874	3,875	103,128	54,559
Net revenues accounted for by individual client, maximum percentage	10.00%	10.00%	10.00%	10.00%
Global Wealth Management [Member]
Net revenues	240,029	225,645	488,377	464,091
Income before income tax expense	61,353	55,426	130,531	116,898
Institutional Group [Member]
Net revenues	135,297	132,915	283,801	259,909
Income before income tax expense	17,546	21,951	41,250	43,344
Other [Member]
Net revenues	(919)	297	2,562	1,470
Income before income tax expense	$ (35,025)	$ (73,502)	$ (68,653)	$ (105,683)