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Borrowings (Subordinated Debentures) (Details) - USD ($) |  | 12 Months Ended |
--- | --- | --- | ---
Oct. 08, 2015 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2015
Debt Instrument [Line Items] |  |  |  |  |
Subordinated Debt | $ 15,000,000.0 | $ 59,331,000 | $ 59,080,000 |  | $ 15,000,000.0
Subordinated Borrowing, Interest Rate | 5.50% |  |  |  |
Debt Instrument, Term |  | 10 years |  |  |
Debt Instrument, Frequency of Periodic Payment |  | semi-annually |  |  |
Debt Instrument, Maturity Date |  | Oct. 15, 2020 |  |  |
Debt Instrument, Call Date, Earliest |  | Oct. 15, 2025 |  |  |
Debt Issuance Cost |  | $ 251,000 | 115,000 |  |
Value Of Trust Preferred Securities Included In Tier 1 Capital |  | 43,000,000.0 | 43,000,000.0 |  | $ 43,000,000.0
Interest Expense, Junior Subordinated Debentures |  | 3,512,000 | $ 3,266,000 | $ 3,415,000 |
Interest rate swaps |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Notional amount of derivative |  | $ 53,000,000.0 |  |  |

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