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Goodwill and Other Intangible Assets (Narrative) (Details) - USD ($) | 3 Months Ended | 12 Months Ended
--- | --- | ---
Sep. 30, 2020 | Dec. 31, 2018 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Finite Lived Intangible Assets [Line Items] |  |  |  |  |
Goodwill impairment |  |  |  | $ 0 | $ 2,350,000
Amortization during the year |  |  | $ 1,134,000 | 1,250,000 | 1,257,000
Core Deposits [Member] |  |  |  |  |
Finite Lived Intangible Assets [Line Items] |  |  |  |  |
Amortization during the year |  |  | 70,000 | 115,000 | 160,000
Other Intangible Assets [Member] |  |  |  |  |
Finite Lived Intangible Assets [Line Items] |  |  |  |  |
Amortization during the year |  |  | 1,100,000 | $ 1,100,000 | 1,100,000
Banking Segment [Member] |  |  |  |  |
Finite Lived Intangible Assets [Line Items] |  |  |  |  |
Goodwill impairment | $ 0 |  |  |  | 0
SDN Reporting Unit [Member] |  |  |  |  |
Finite Lived Intangible Assets [Line Items] |  |  |  |  |
Goodwill impairment |  | $ 2,400,000 | $ 0 |  |
Courier Capital [Member] |  |  |  |  |
Finite Lived Intangible Assets [Line Items] |  |  |  |  |
Goodwill impairment |  |  |  |  | 0
HNP Capital [Member] |  |  |  |  |
Finite Lived Intangible Assets [Line Items] |  |  |  |  |
Goodwill impairment |  |  |  |  | $ 0

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