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Servicing Rights - Narrative (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | ---
Sep. 30, 2020 | Sep. 30, 2019 | Sep. 30, 2020 | Sep. 30, 2019 | Dec. 31, 2019
Servicing Assets at Fair Value [Line Items] |  |  |  |  |
Servicing rights | $ 10,589 |  | $ 10,589 |  | $ 11,920
Other Noninterest Income |  |  |  |  |
Servicing Assets at Fair Value [Line Items] |  |  |  |  |
Mortgage servicing fees | 671 | $ 616 | 2,000 | $ 1,800 |
Commercial servicing rights |  |  |  |  |
Servicing Assets at Fair Value [Line Items] |  |  |  |  |
Servicing rights | 1,286 |  | 1,286 |  | 1,214
Commercial loans serviced for a third party | $ 267,900 |  | $ 267,900 |  | $ 252,900
Constant prepayment rate (percent) |  |  | 12.25% |  | 12.25%
Discount rate (percent) |  |  | 11.70% |  | 11.70%

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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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- Definition Discount rate used to estimate the fair value of servicing assets and servicing liabilities. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 50 -Section 50 -Paragraph 2 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=116651436&loc=d3e122596-111746 + Details
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- Definition Estimated rate of prepayments of principal on servicing assets and servicing liabilities. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 50 -Section 50 -Paragraph 2 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=116651436&loc=d3e122596-111746 + Details
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