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Other Real Estate Owned (Details) - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Repossessed Assets [Abstract] |  |  |
Real Estate Acquired Through Foreclosure, Valuation Adjustments | $ 0.1 | $ 0.9 |
Real Estate Acquired Through Foreclosure [Roll Forward] |  |  |
Balance at beginning of year | 8.5 | 14.4 | $ 10.1
OREO acquired through acquisitions | 0.0 | 2.4 | 0.6
Additions | 3.3 | 14.1 | 12.1
Valuation adjustments | (0.1) | (0.9) | (0.1)
Dispositions | (9.2) | (21.8) | (8.3)
Balance at end of year | 2.5 | 8.5 | 14.4
Real Estate Acquired Through Foreclosure, Improvements | 0.0 | 0.3 | 0.0
Write-downs of OREO | (0.1) | (0.9) | $ (0.1)
Mortgage Loans in Process of Foreclosure, Amount | 0.2 | 0.4 |
Carrying value of foreclosed OREO | $ 0.0 | $ 2.3 |

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- Definition The charge against earnings in the period to reduce the carrying amount of real property to fair value. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109226691&loc=d3e2921-110230 + Details
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