Goodwill and Intangible Assets (Carrying Amount Of Goodwill And Intangible Assets) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Schedule of Goodwill and Intangible Assets [Line Items]
Goodwill, Beginning balance	$ 1,194,074
Goodwill, Adjustments	412
Goodwill, Sale of ZCM	(9,972)
Goodwill, Ending balance	1,184,514
Intangible assets, Beginning balance	161,773
Intangible assets, Adjustments / Sale of ZCM	(2,095)
Intangible assets, Amortization	(5,032)	$ (3,593)
Intangible assets, Ending balance	154,646
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
Intangible assets, Beginning balance	53,279
Intangible assets, Adjustments / Sale of ZCM	(1,532)
Intangible assets, Amortization	(1,735)
Intangible assets, Ending balance	50,012
Institutional Group [Member]
Schedule of Goodwill and Intangible Assets [Line Items]
Goodwill, Beginning balance	849,093
Goodwill, Adjustments	412
Goodwill, Ending balance	849,505
Intangible assets, Beginning balance	108,494
Intangible assets, Adjustments / Sale of ZCM	(563)
Intangible assets, Amortization	(3,297)
Intangible assets, Ending balance	$ 104,634