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Loans and Allowance for Loan Losses - Purchased Credit-Impaired (Details) $ in Thousands | 3 Months Ended | 9 Months Ended | 81 Months Ended |
--- | --- | --- | --- | ---
Sep. 30, 2018 USD ($) | Sep. 30, 2017 USD ($) | Sep. 30, 2018 USD ($) | Sep. 30, 2017 USD ($) | Nov. 21, 2017 acquisition | Dec. 31, 2017 USD ($)
Business Acquisitions, Purchased Credit-Impaired Loans [Line Items] |  |  |  |  |  |
Number of banks acquired | acquisition |  |  |  |  | 3 |
PCI Loans, Carrying Value [Abstract] |  |  |  |  |  |
Unpaid Principal Balance | $ 2,621 |  | $ 2,621 |  |  | $ 2,868
Carrying Value | 2,129 |  | 2,129 |  |  | 2,115
Accretable Yield [Roll Forward] |  |  |  |  |  |
Balance at beginning of period | 1,059 | $ 1,306 | 1,254 | $ 1,476 |  |
Accretion | (63) | (76) | (258) | (246) |  |
Balance at end of period | 996 | $ 1,230 | 996 | $ 1,230 |  |
Commercial loans | Commercial and industrial |  |  |  |  |  |
PCI Loans, Carrying Value [Abstract] |  |  |  |  |  |
Unpaid Principal Balance | 106 |  | 106 |  |  | 276
Carrying Value | 39 |  | 39 |  |  | 65
Commercial real estate loans | Commercial real estate, owner-occupied |  |  |  |  |  |
PCI Loans, Carrying Value [Abstract] |  |  |  |  |  |
Unpaid Principal Balance | 1,259 |  | 1,259 |  |  | 1,297
Carrying Value | 1,198 |  | 1,198 |  |  | 1,166
Commercial real estate loans | Commercial real estate, investor |  |  |  |  |  |
PCI Loans, Carrying Value [Abstract] |  |  |  |  |  |
Unpaid Principal Balance | 1,041 |  | 1,041 |  |  | 1,064
Carrying Value | 806 |  | 806 |  |  | 790
Residential loans | Home equity |  |  |  |  |  |
PCI Loans, Carrying Value [Abstract] |  |  |  |  |  |
Unpaid Principal Balance | 215 |  | 215 |  |  | 231
Carrying Value | $ 86 |  | $ 86 |  |  | $ 94

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- Definition Amount of the excess of a loan's cash flows expected to be collected over the investor's initial investment in acquired loans not accounted for as debt securities with evidence of deterioration of credit quality. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 30 -Section 15 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=82894507&loc=d3e13503-111538 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=82894903&loc=d3e15032-111544 + Details
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- Definition The recorded balance, net of any applicable reductions (for example, unamortized accretable yield and allowance for loan losses). This relates to loans not accounted for debt securities with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=82894903&loc=d3e15032-111544 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 30 -Section 15 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=82894507&loc=d3e13503-111538 + Details
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