Segment Reporting (Schedule Of Information Of Total Assets On Segment Basis) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Total assets	$ 21,715,342	$ 21,383,953
Global Wealth Management [Member]
Segment Reporting Information [Line Items]
Total assets	17,950,069	17,717,617
Institutional Group [Member]
Segment Reporting Information [Line Items]
Total assets	3,402,714	3,313,304
Other [Member]
Segment Reporting Information [Line Items]
Total assets	$ 362,559	$ 353,032