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Fair Value Measurements - Quantitative and Qualitative Information (Details) $ in Thousands | Sep. 30, 2020 USD ($) | Dec. 31, 2019 USD ($)
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Quantitative information about Level 3 fair value measurements |  |
Mortgage servicing rights, fair value | $ 5,010 | $ 5,935
Securities available-for-sale, at fair value | 448,421 | 484,648
Level 3 |  |
Quantitative information about Level 3 fair value measurements |  |
Mortgage servicing rights, fair value | 5,010 | 5,935
Securities available-for-sale, at fair value | 4,790 | 5,419
US States and Political Subdivisions Debt Securities [Member] |  |
Quantitative information about Level 3 fair value measurements |  |
Securities available-for-sale, at fair value | 249,777 | 249,175
US States and Political Subdivisions Debt Securities [Member] | Level 3 |  |
Quantitative information about Level 3 fair value measurements |  |
Securities available-for-sale, at fair value | 4,800 | 5,900
Collateralized Mortgage Obligations [Member] |  |
Quantitative information about Level 3 fair value measurements |  |
Securities available-for-sale, at fair value | $ 57,013 | $ 57,984
Measurement Input, Discount Rate | Mortgage Servicing Rights [Member] | Level 3 | Minimum [Member] |  |
Quantitative information about Level 3 fair value measurements |  |
Servicing Asset, Measurement Input | 11.0 | 10.0
Measurement Input, Discount Rate | Mortgage Servicing Rights [Member] | Level 3 | Maximum [Member] |  |
Quantitative information about Level 3 fair value measurements |  |
Servicing Asset, Measurement Input | 15.0 | 58.8
Measurement Input, Discount Rate | Mortgage Servicing Rights [Member] | Level 3 | Weighted Average [Member] |  |
Quantitative information about Level 3 fair value measurements |  |
Servicing Asset, Measurement Input | 11.0 | 10.1
Measurement Input, Constant Prepayment Rate | Mortgage Servicing Rights [Member] | Level 3 | Minimum [Member] |  |
Quantitative information about Level 3 fair value measurements |  |
Servicing Asset, Measurement Input | 0.0 | 0.0
Measurement Input, Constant Prepayment Rate | Mortgage Servicing Rights [Member] | Level 3 | Maximum [Member] |  |
Quantitative information about Level 3 fair value measurements |  |
Servicing Asset, Measurement Input | 42.8 | 69.0
Measurement Input, Constant Prepayment Rate | Mortgage Servicing Rights [Member] | Level 3 | Weighted Average [Member] |  |
Quantitative information about Level 3 fair value measurements |  |
Servicing Asset, Measurement Input | 15.4 | 14.1
Recurring |  |
Quantitative information about Level 3 fair value measurements |  |
Securities available-for-sale, at fair value |  | $ 8,337

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- Definition Fair value of an asset representing net future revenue from contractually specified servicing fees, late charges, and other ancillary revenues, in excess of future costs related to servicing arrangements. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 50 -Section 45 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6469459&loc=d3e122501-111745 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 50 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6469459&loc=d3e122492-111745 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 50 -Section 50 -Paragraph 3 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=116651436&loc=d3e122625-111746 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 50 -Section 45 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6469459&loc=d3e122501-111745 + Details
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