Goodwill and Intangible Assets (Intangible Assets) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 254,587	$ 259,102
Accumulated Amortization	109,115	97,329
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	203,188	207,253
Accumulated Amortization	82,990	75,987
Trade Name [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	28,659	28,659
Accumulated Amortization	15,196	13,649
Core Deposits [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	8,615	8,615
Accumulated Amortization	4,387	2,985
Non-Compete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	9,240	9,490
Accumulated Amortization	3,825	2,828
Investment Banking Backlog [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	840	4,245
Accumulated Amortization	303	1,787
Acquired Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	4,045	840
Accumulated Amortization	$ 2,414	$ 93

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

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- Definition

Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 928
-SubTopic 340
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6473545&loc=d3e61844-108004

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

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- Definition

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