Goodwill and Intangible Assets (Carrying Amount Of Goodwill And Intangible Assets) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Schedule of Goodwill and Intangible Assets [Line Items]
Goodwill, Beginning balance			$ 1,194,074
Goodwill, Adjustments			(3,400)
Goodwill, Sale of ZCM			(9,972)
Goodwill, Ending balance	$ 1,180,702		1,180,702
Intangible assets, Beginning balance			161,773
Intangible assets, Adjustments / Sale of ZCM			(2,172)
Intangible assets, Amortization	(4,700)	$ (3,500)	(9,760)	$ (7,140)
Intangible assets, Ending balance	149,841		149,841
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			(3,382)
Intangible assets, Ending balance	48,365		48,365
Institutional Group [Member]
Schedule of Goodwill and Intangible Assets [Line Items]
Goodwill, Beginning balance			849,093
Goodwill, Adjustments			(3,400)
Goodwill, Ending balance	845,693		845,693
Intangible assets, Beginning balance			108,494
Intangible assets, Adjustments / Sale of ZCM			(640)
Intangible assets, Amortization			(6,378)
Intangible assets, Ending balance	$ 101,476		$ 101,476