Segment Reporting (Schedule Of Operating Information, Segment) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Net revenues	[1]	$ 883,300	$ 821,572	$ 2,692,151	$ 2,392,779
Income/(loss) before income taxes		158,393	150,754	416,459	436,545
Global Wealth Management [Member]
Segment Reporting Information [Line Items]
Net revenues	[1]	526,836	534,571	1,615,574	1,577,614
Income/(loss) before income taxes		178,930	202,823	529,422	589,665
Institutional Group [Member]
Segment Reporting Information [Line Items]
Net revenues	[1]	363,365	290,222	1,093,699	822,110
Income/(loss) before income taxes		76,841	48,623	201,630	120,129
Other Segments [Member]
Segment Reporting Information [Line Items]
Net revenues	[1]	(6,901)	(3,221)	(17,122)	(6,945)
Income/(loss) before income taxes		$ (97,378)	$ (100,692)	$ (314,593)	$ (273,249)

[1] No individual client accounted for more than 10 percent of total net revenues for the three and nine months ended September 30, 2020 or 2019.