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Allowance for Loan Losses - Investments in Loans Considered to be Impaired and Related Information on Impaired Loans (Details) - USD ($) $ in Thousands | 3 Months Ended |
--- | --- | ---
Mar. 31, 2018 | Mar. 31, 2017 | Dec. 31, 2017
Financing Receivable, Impaired [Line Items] |  |  |
With a related allowance recorded, Recorded Investment | $ 695 |  | $ 1,783
With a related allowance recorded, Unpaid Principal Balance | 710 |  | 1,835
Impaired Financing Receivable, Related Allowance | 576 |  | 77
Without a related allowance recorded, Recorded Investment | 29,197 |  | 25,040
Without a related allowance, Unpaid Principal Balance | 33,964 |  | 31,302
Impaired Financing Receivable, Recorded Investment | 29,892 |  | 26,823
Impaired Financing Receivable, Unpaid Principal Balance, Total | 34,674 |  | 33,137
With a related allowance recorded, Average Recorded Investment | 628 | $ 10,035 |
With a related allowance recorded, Interest Income Recognized | 12 | 72 |
Without a related allowance recorded, Average Recorded Investment | 24,779 | 37,944 |
Without a related allowance recorded, Interest Income Recognized | 327 | 242 |
Impaired Financing Receivable, Average Recorded Investment, Total | 25,407 | 47,979 |
Impaired Financing Receivable, Interest Income Recognized, Total | 339 | 314 |
Commercial real estate |  |  |
Financing Receivable, Impaired [Line Items] |  |  |
With a related allowance recorded, Recorded Investment | 0 |  | 0
With a related allowance recorded, Unpaid Principal Balance | 0 |  | 0
Impaired Financing Receivable, Related Allowance | 0 |  | 0
Without a related allowance recorded, Recorded Investment | 3,774 |  | 3,546
Without a related allowance, Unpaid Principal Balance | 4,034 |  | 3,811
Impaired Financing Receivable, Recorded Investment | 3,774 |  | 3,546
Impaired Financing Receivable, Unpaid Principal Balance, Total | 4,034 |  | 3,811
With a related allowance recorded, Average Recorded Investment | 0 | 0 |
With a related allowance recorded, Interest Income Recognized | 0 | 0 |
Without a related allowance recorded, Average Recorded Investment | 3,817 | 8,581 |
Without a related allowance recorded, Interest Income Recognized | 43 | 33 |
Impaired Financing Receivable, Average Recorded Investment, Total | 3,817 | 8,581 |
Impaired Financing Receivable, Interest Income Recognized, Total | 43 | 33 |
Commercial and industrial |  |  |
Financing Receivable, Impaired [Line Items] |  |  |
With a related allowance recorded, Recorded Investment | 656 |  | 1,735
With a related allowance recorded, Unpaid Principal Balance | 671 |  | 1,787
Impaired Financing Receivable, Related Allowance | 537 |  | 29
Without a related allowance recorded, Recorded Investment | 11,917 |  | 5,549
Without a related allowance, Unpaid Principal Balance | 13,972 |  | 7,980
Impaired Financing Receivable, Recorded Investment | 12,573 |  | 7,284
Impaired Financing Receivable, Unpaid Principal Balance, Total | 14,643 |  | 9,767
With a related allowance recorded, Average Recorded Investment | 586 | 10,008 |
With a related allowance recorded, Interest Income Recognized | 11 | 72 |
Without a related allowance recorded, Average Recorded Investment | 6,688 | 11,410 |
Without a related allowance recorded, Interest Income Recognized | 110 | 43 |
Impaired Financing Receivable, Average Recorded Investment, Total | 7,274 | 21,418 |
Impaired Financing Receivable, Interest Income Recognized, Total | 121 | 115 |
Commercial construction |  |  |
Financing Receivable, Impaired [Line Items] |  |  |
With a related allowance recorded, Recorded Investment | 0 |  | 0
With a related allowance recorded, Unpaid Principal Balance | 0 |  | 0
Impaired Financing Receivable, Related Allowance | 0 |  | 0
Without a related allowance recorded, Recorded Investment | 3,444 |  | 5,464
Without a related allowance, Unpaid Principal Balance | 4,954 |  | 8,132
Impaired Financing Receivable, Recorded Investment | 3,444 |  | 5,464
Impaired Financing Receivable, Unpaid Principal Balance, Total | 4,954 |  | 8,132
With a related allowance recorded, Average Recorded Investment | 0 | 0 |
With a related allowance recorded, Interest Income Recognized | 0 | 0 |
Without a related allowance recorded, Average Recorded Investment | 3,446 | 6,239 |
Without a related allowance recorded, Interest Income Recognized | 36 | 37 |
Impaired Financing Receivable, Average Recorded Investment, Total | 3,446 | 6,239 |
Impaired Financing Receivable, Interest Income Recognized, Total | 36 | 37 |
Consumer real estate |  |  |
Financing Receivable, Impaired [Line Items] |  |  |
With a related allowance recorded, Recorded Investment | 0 |  | 21
With a related allowance recorded, Unpaid Principal Balance | 0 |  | 21
Impaired Financing Receivable, Related Allowance | 0 |  | 21
Without a related allowance recorded, Recorded Investment | 10,052 |  | 10,467
Without a related allowance, Unpaid Principal Balance | 10,987 |  | 11,357
Impaired Financing Receivable, Recorded Investment | 10,052 |  | 10,488
Impaired Financing Receivable, Unpaid Principal Balance, Total | 10,987 |  | 11,378
With a related allowance recorded, Average Recorded Investment | 0 | 26 |
With a related allowance recorded, Interest Income Recognized | 0 | 0 |
Without a related allowance recorded, Average Recorded Investment | 10,816 | 11,692 |
Without a related allowance recorded, Interest Income Recognized | 138 | 129 |
Impaired Financing Receivable, Average Recorded Investment, Total | 10,816 | 11,718 |
Impaired Financing Receivable, Interest Income Recognized, Total | 138 | 129 |
Other consumer |  |  |
Financing Receivable, Impaired [Line Items] |  |  |
With a related allowance recorded, Recorded Investment | 39 |  | 27
With a related allowance recorded, Unpaid Principal Balance | 39 |  | 27
Impaired Financing Receivable, Related Allowance | 39 |  | 27
Without a related allowance recorded, Recorded Investment | 10 |  | 14
Without a related allowance, Unpaid Principal Balance | 17 |  | 22
Impaired Financing Receivable, Recorded Investment | 49 |  | 41
Impaired Financing Receivable, Unpaid Principal Balance, Total | 56 |  | $ 49
With a related allowance recorded, Average Recorded Investment | 42 | 1 |
With a related allowance recorded, Interest Income Recognized | 1 | 0 |
Without a related allowance recorded, Average Recorded Investment | 12 | 22 |
Without a related allowance recorded, Interest Income Recognized | 0 | 0 |
Impaired Financing Receivable, Average Recorded Investment, Total | 54 | 23 |
Impaired Financing Receivable, Interest Income Recognized, Total | $ 1 | $ 0 |

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