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Allowance for Loan Losses and Credit Quality of Loans, Average Recorded Investments on Loans Specifically Evaluated for Impairment and Interest Income Recognized (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Average Recorded Investment and Interest Income Recognized [Abstract] |  |  |
Average recorded investment | $ 19,733 | $ 20,429 | $ 23,238
Interest income recognized accrual | 891 | 901 | 924
Originated Loans [Member] |  |  |
Average Recorded Investment and Interest Income Recognized [Abstract] |  |  |
Average recorded investment | 19,733 | 20,429 | 23,145
Interest income recognized accrual | 891 | 901 | 924
Originated Loans [Member] | Commercial Loans [Member] |  |  |
Average Recorded Investment and Interest Income Recognized [Abstract] |  |  |
Average recorded investment | 4,642 | 5,549 | 8,183
Interest income recognized accrual | 148 | 155 | 171
Originated Loans [Member] | Commercial Loans [Member] | C&I [Member] |  |  |
Average Recorded Investment and Interest Income Recognized [Abstract] |  |  |
Average recorded investment | 242 | 453 | 0
Interest income recognized accrual | 1 | 1 | 0
Originated Loans [Member] | Commercial Loans [Member] | CRE [Member] |  |  |
Average Recorded Investment and Interest Income Recognized [Abstract] |  |  |
Average recorded investment | 3,311 | 4,078 | 0
Interest income recognized accrual | 123 | 128 | 0
Originated Loans [Member] | Commercial Loans [Member] | Commercial [Member] |  |  |
Average Recorded Investment and Interest Income Recognized [Abstract] |  |  |
Average recorded investment | 0 | 0 | 1,841
Interest income recognized accrual | 0 | 0 | 0
Originated Loans [Member] | Commercial Loans [Member] | Commercial Real Estate [Member] |  |  |
Average Recorded Investment and Interest Income Recognized [Abstract] |  |  |
Average recorded investment | 0 | 0 | 3,534
Interest income recognized accrual | 0 | 0 | 115
Originated Loans [Member] | Commercial Loans [Member] | Agricultural [Member] |  |  |
Average Recorded Investment and Interest Income Recognized [Abstract] |  |  |
Average recorded investment | 0 | 0 | 224
Interest income recognized accrual | 0 | 0 | 1
Originated Loans [Member] | Commercial Loans [Member] | Agricultural Real Estate [Member] |  |  |
Average Recorded Investment and Interest Income Recognized [Abstract] |  |  |
Average recorded investment | 0 | 0 | 1,709
Interest income recognized accrual | 0 | 0 | 43
Originated Loans [Member] | Commercial Loans [Member] | Business Banking [Member] |  |  |
Average Recorded Investment and Interest Income Recognized [Abstract] |  |  |
Average recorded investment | 1,089 | 1,018 | 875
Interest income recognized accrual | 24 | 26 | 12
Originated Loans [Member] | Consumer Loans [Member] |  |  |
Average Recorded Investment and Interest Income Recognized [Abstract] |  |  |
Average recorded investment | 7,586 | 8,101 | 8,439
Interest income recognized accrual | 393 | 441 | 457
Originated Loans [Member] | Consumer Loans [Member] | Indirect Auto [Member] |  |  |
Average Recorded Investment and Interest Income Recognized [Abstract] |  |  |
Average recorded investment | 192 | 179 | 0
Interest income recognized accrual | 10 | 10 | 0
Originated Loans [Member] | Consumer Loans [Member] | Direct [Member] |  |  |
Average Recorded Investment and Interest Income Recognized [Abstract] |  |  |
Average recorded investment | 7,387 | 7,922 | 0
Interest income recognized accrual | 382 | 431 | 0
Originated Loans [Member] | Consumer Loans [Member] | Specialty Lending [Member] |  |  |
Average Recorded Investment and Interest Income Recognized [Abstract] |  |  |
Average recorded investment | 7 | 0 | 0
Interest income recognized accrual | 1 | 0 | 0
Originated Loans [Member] | Consumer Loans [Member] | Indirect [Member] |  |  |
Average Recorded Investment and Interest Income Recognized [Abstract] |  |  |
Average recorded investment | 0 | 0 | 35
Interest income recognized accrual | 0 | 0 | 3
Originated Loans [Member] | Consumer Loans [Member] | Home Equity [Member] |  |  |
Average Recorded Investment and Interest Income Recognized [Abstract] |  |  |
Average recorded investment | 0 | 0 | 8,226
Interest income recognized accrual | 0 | 0 | 446
Originated Loans [Member] | Consumer Loans [Member] | Direct [Member] |  |  |
Average Recorded Investment and Interest Income Recognized [Abstract] |  |  |
Average recorded investment | 0 | 0 | 178
Interest income recognized accrual | 0 | 0 | 8
Originated Loans [Member] | Residential Real Estate [Member] |  |  |
Average Recorded Investment and Interest Income Recognized [Abstract] |  |  |
Average recorded investment | 7,505 | 6,779 | 6,523
Interest income recognized accrual | 350 | 305 | 296
Acquired Loans [Member] |  |  |
Average Recorded Investment and Interest Income Recognized [Abstract] |  |  |
Average recorded investment | 0 | 0 | 93
Interest income recognized accrual | 0 | 0 | 0
Acquired Loans [Member] | Commercial Loans [Member] |  |  |
Average Recorded Investment and Interest Income Recognized [Abstract] |  |  |
Average recorded investment | 0 | 0 | 93
Interest income recognized accrual | 0 | 0 | 0
Acquired Loans [Member] | Commercial Loans [Member] | Commercial Real Estate [Member] |  |  |
Average Recorded Investment and Interest Income Recognized [Abstract] |  |  |
Average recorded investment | 0 | 0 | 93
Interest income recognized accrual | $ 0 | $ 0 | $ 0

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