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Restructuring Charges (Narrative) (Details) $ in Thousands |  | 1 Months Ended | 3 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | --- | --- | ---
Jul. 17, 2020 Branch | Oct. 31, 2020 Branch | Sep. 30, 2021 USD ($) | Sep. 30, 2020 USD ($) | Sep. 30, 2021 USD ($) | Sep. 30, 2020 USD ($) | Dec. 31, 2020 USD ($)
Restructuring Cost And Reserve [Line Items] |  |  |  |  |  |  |
Number of bank branch closure | Branch | 6 |  |  |  |  |  |
Percentage of branch network | 10.00% |  |  |  |  |  |
Percentage of branch network impact | 6.00% |  |  |  |  |  |
Number of additional branches planned to close | Branch |  | 1 |  |  |  |  |
Pre tax expense related branch closures |  |  |  |  |  |  | $ 1,700
Total costs result in future cash expenditures |  |  |  |  |  |  | 800
Anticipates annual expense savings branch closures |  |  |  |  |  |  | 2,700
Restructuring charges |  |  |  | $ 1,586 |  | $ 1,586 |
Other Assets [Member] |  |  |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |  |  |
Reclassification of long-lived assets to held for sale |  |  | $ 4,700 |  | $ 4,700 |  | 0
Employee Severance [Member] |  |  |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |  |  |
Pre tax expense related branch closures |  |  |  |  |  |  | 200
Lease Termination Costs [Member] |  |  |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |  |  |
Pre tax expense related branch closures |  |  |  |  |  |  | 500
Valuation Adjustments On Branch Facilities [Member] |  |  |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |  |  |
Pre tax expense related branch closures |  |  |  |  |  |  | $ 1,000

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