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Fair Value Measurements - Narrative (Details) - USD ($) $ in Millions | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
--- | --- | --- | ---
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Related allowance | $ 3.6 | $ 6.8 | $ 10.8
Fair Value, Nonrecurring [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Impaired loans | 13.7 | 12.2 |
Fair Value, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Related allowance | 3.6 | 6.8 |
Partial loan charge-off | 10.1 | 5.4 |
Carrying Amount | Fair Value, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Impaired loans | 41.3 | 36.3 |
Assets Held-for-sale, Long Lived, Fair Value Disclosure | 6.4 | 5.4 |
Changes Measurement [Member] | Fair Value, Nonrecurring [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Assets Held-for-sale, Long Lived, Fair Value Disclosure | 0.2 | 0.5 |
Estimated Fair Value | Fair Value, Nonrecurring [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Assets Held-for-sale, Long Lived, Fair Value Disclosure | 6.2 | 4.9 |
Estimated Fair Value | Fair Value, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Impaired loans | $ 27.6 | $ 24.1 |

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