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Other Real Estate Owned (Details) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 30, 2017 | Dec. 31, 2017
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items] |  |  |  |  |
Real Estate Acquired Through Foreclosure, Acquired Through Acquisition | $ 0.0 | $ 1.1 | $ 0.0 | $ 1.1 |
Real Estate Acquired Through Foreclosure [Roll Forward] |  |  |  |  |
Beginning balance | 11.0 | 9.4 | 10.1 | 10.0 |
Additions | 6.3 | 1.4 | 7.4 | 1.8 |
Valuation adjustments | 0.0 | 0.0 | 0.0 | (0.1) |
Dispositions | (2.4) | (0.6) | (2.6) | (1.5) |
Ending balance | 14.9 | $ 11.3 | 14.9 | $ 11.3 |
Consumer mortgage loans collateralized by residential real estate property in the process of foreclosure | 2.5 |  | 2.5 |  | $ 0.0
Residential real estate |  |  |  |  |
Real Estate Acquired Through Foreclosure [Roll Forward] |  |  |  |  |
Beginning balance |  |  | 2.7 |  |
Ending balance | $ 2.6 |  | $ 2.6 |  |

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- Definition Recorded investment of consumer mortgage loan receivables secured by residential real estate properties for which formal foreclosure proceedings are in process. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 35 -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL49126937-111524 + Details
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