Goodwill and Intangible Assets (Intangible Assets) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 254,023	$ 253,941
Accumulated Amortization	117,247	112,957
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	202,424	202,342
Accumulated Amortization	87,941	85,152
Trade Name [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	28,659	28,659
Accumulated Amortization	16,097	15,660
Non-Compete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	9,240	9,240
Accumulated Amortization	4,586	4,229
Core Deposits [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	8,615	8,615
Accumulated Amortization	5,210	4,809
Investment Banking Backlog [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	4,245	4,245
Accumulated Amortization	2,970	2,734
Acquired Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	840	840
Accumulated Amortization	$ 443	$ 373