Goodwill And Intangible Assets (Intangible Assets Subject To Amortization) (Details) - USD ($) $ in Thousands		Mar. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value		$ 187,848	$ 175,716
Accumulated Amortization		70,997	68,207
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value		147,101	146,986
Accumulated Amortization		58,056	55,809
Trade Name [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value		24,713	24,713
Accumulated Amortization		10,610	10,228
Investment Banking Backlog [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value		2,603	2,598
Accumulated Amortization		1,273	1,202
Non-Compete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value		1,431	1,419
Accumulated Amortization		1,058	$ 968
Estimated Ziegler Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	[1]	$ 12,000

[1] See discussion regarding the allocation of the estimated goodwill and intangibles recorded for the Ziegler acquisition.