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Loans (Narrative) (Details) | 12 Months Ended
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Dec. 31, 2020 USD ($) contract | Dec. 31, 2019 USD ($) contract | Dec. 31, 2018 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans | $ 3,542,718,000 | $ 3,190,505,000 |
Loans, related parties | 32,800,000 | 18,600,000 |
Loans, related parties, new borrowings | 16,300,000 |  |
Loans, related parties, repayments and other reductions | 2,100,000 |  |
Past due greater than 90 days and still accruing interest | 0 | 0 |
Interest income recognized on nonaccrual loans | 0 | 0 | $ 0
Estimated interest income | $ 430,000 | $ 508,000 | $ 294,000
Number of loans modified as TDR | contract | 0 | 0 |
Number of loans modified as TDR that defaulted | contract | 0 | 0 |
Days past due when loans are generally placed on nonaccrual status, in days | 90 days | 90 days |
Consumer Overdrafts [Member] |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Past due greater than 90 days and still accruing interest | $ 231,000 | $ 6,000 |
Other Assets [Member] |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Accrued interest receivable | 13,600,000 | $ 9,100,000 |
Deferral [Member] |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans | 113,000,000.0 |  |
Paycheck Protection Program [Member] |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans | 253,100,000 |  |
COVID-19 [Member] |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans | $ 532,400,000 |  |

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- Definition Number of financing receivables that have been modified by troubled debt restructurings. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953676-111524 + Details
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- Definition Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=121593590&loc=d3e4428-111522 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.7) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 + Details
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