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Mortgage Servicing Rights (Narrative) (Details) - USD ($) | 3 Months Ended |
--- | --- | ---
Mar. 31, 2021 | Mar. 31, 2020 | Dec. 31, 2020
Mortgage Servicing Rights [Abstract] |  |  |
Residential Mortgage Loans Serviced | $ 3,300,000,000 |  | $ 3,300,000,000
Contractually Specified Servicing Fee, Late Fee, and Ancillary Fee Earned in Exchange for Servicing Financial Asset | 2,100,000 | $ 2,100,000 |
Valuation allowance increase | $ (3,123,000) | $ 2,967,000 |

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- Definition Mortgage Servicing Rights [Abstract] + References No definition available. + Details
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- Definition Unpaid principal balance of residential mortgage loans serviced for others at period end. + References No definition available. + Details
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- Definition Amount of contractually specified servicing fee, late fee, and ancillary fee recognized as income for servicing asset and servicing liability. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 50 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=116651436&loc=d3e122596-111746 + Details
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- Definition Amount of increase (decrease) in the valuation allowance for impairment of contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer from expenses (recoveries) recognized. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 50 -Section 50 -Paragraph 4 -Subparagraph (e)(2) -URI http://asc.fasb.org/extlink&oid=116651436&loc=d3e122739-111746 + Details
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