Segment Reporting (Schedule Of Operating Information, Segment) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting Information [Line Items]
Net revenues	[1]	$ 721,169	$ 641,986	$ 2,122,347	$ 1,914,105
Income/(loss) before income taxes		108,139	27,982	270,356	87,688
Global Wealth Management [Member]
Segment Reporting Information [Line Items]
Net revenues	[1]	453,558	390,032	1,348,280	1,155,875
Income/(loss) before income taxes		161,756	109,079	457,045	307,466
Institutional Group [Member]
Segment Reporting Information [Line Items]
Net revenues	[1]	264,747	258,800	778,367	760,996
Income/(loss) before income taxes		51,717	44,923	144,481	116,628
Other [Member]
Segment Reporting Information [Line Items]
Net revenues	[1]	2,864	(6,846)	(4,300)	(2,766)
Income/(loss) before income taxes		$ (105,334)	$ (126,020)	$ (331,170)	$ (336,406)

[1] No individual client accounted for more than 10 percent of total net revenues for the three and nine months ended September 30, 2017 or 2016.