Goodwill and Intangible Assets (Carrying Amount Of Goodwill And Intangible Assets) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Schedule of Goodwill and Intangible Assets [Line Items]
Goodwill, Beginning balance			$ 1,194,074
Goodwill, Adjustments			(2,104)
Goodwill, Sale of ZCM			(9,972)
Goodwill, Ending balance	$ 1,181,998		1,181,998
Intangible assets, Beginning balance			161,773
Intangible assets, Adjustments / Sale of ZCM			(1,812)
Intangible assets, Amortization	(4,700)	$ (3,800)	(14,489)	$ (10,960)
Intangible assets, Ending balance	145,472		145,472
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		335,009
Intangible assets, Beginning balance			53,279
Intangible assets, Adjustments / Sale of ZCM			(1,532)
Intangible assets, Amortization			(5,006)
Intangible assets, Ending balance	46,741		46,741
Institutional Group [Member]
Schedule of Goodwill and Intangible Assets [Line Items]
Goodwill, Beginning balance			849,093
Goodwill, Adjustments			(2,104)
Goodwill, Ending balance	846,989		846,989
Intangible assets, Beginning balance			108,494
Intangible assets, Adjustments / Sale of ZCM			(280)
Intangible assets, Amortization			(9,483)
Intangible assets, Ending balance	$ 98,731		$ 98,731