Segment Reporting (Schedule Of Operating Information, Segment) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013 item		Mar. 31, 2012
Number of business segments	3
Number of businesses within reportable segment	2
Net revenues	$ 441,780	[1]	$ 400,333	[1]
Income before income tax expense	23,346		59,254
Net revenues accounted for by individual client, maximum percentage	10.00%
Global Wealth Management [Member]
Net revenues	266,957	[1]	247,608	[1]
Income before income tax expense	69,499		68,878
Institutional Group [Member]
Net revenues	176,437	[1]	149,244	[1]
Income before income tax expense	28,137		24,004
Other [Member]
Net revenues	(1,614)	[1]	3,481	[1]
Income before income tax expense	$ (74,290)		$ (33,628)

[1] No individual client accounted for more than 10 percent of total net revenues for the three months ended March 31, 2013 or 2012.