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21) Mortgage Servicing Rights: Assumptions used in determining MSR value (Details) - Decimal | 12 Months Ended
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Dec. 31, 2020 | Dec. 31, 2019
Text Block [Abstract] |  |
Prepayment Speeds | 15.60 | 15.30
Average Life in Years of MSR | 5 years 3 months 19 days | 5 years 3 months 8 days
Discount Rate | 9.50 | 9.51

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