Goodwill and Intangible Assets (Carrying Amount Of Goodwill And Intangible Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Schedule of Goodwill and Intangible Assets [Line Items]
Goodwill, Beginning balance	$ 1,194,074
Goodwill, Net Adjustments	(2,104)
Goodwill, Sale of ZCM	(9,972)
Goodwill, Ending balance	1,181,998	$ 1,194,074
Intangible assets, Beginning balance	161,773
Intangible assets, Adjustments / Sale of ZCM	(1,169)
Intangible assets, Amortization	(19,620)	(16,015)	$ (12,557)
Intangible assets, Ending balance	140,984	161,773
Global Wealth Management [Member]
Schedule of Goodwill and Intangible Assets [Line Items]
Goodwill, Beginning balance	344,981
Goodwill, Sale of ZCM	(9,972)
Goodwill, Ending balance	335,009	344,981
Intangible assets, Beginning balance	53,279
Intangible assets, Adjustments / Sale of ZCM	(1,532)
Intangible assets, Amortization	(7,076)
Intangible assets, Ending balance	44,671	53,279
Institutional Group [Member]
Schedule of Goodwill and Intangible Assets [Line Items]
Goodwill, Beginning balance	849,093
Goodwill, Net Adjustments	(2,104)
Goodwill, Ending balance	846,989	849,093
Intangible assets, Beginning balance	108,494
Intangible assets, Adjustments / Sale of ZCM	363
Intangible assets, Amortization	(12,544)
Intangible assets, Ending balance	$ 96,313	$ 108,494