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Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions | Dec. 31, 2018 | Dec. 31, 2017
--- | --- | ---
Deferred tax assets: |  |
Loans, principally due to allowance for loan losses | $ 18.4 | $ 18.0
Loan discount | 8.3 | 6.7
Investment securities, unrealized losses | 8.9 | 5.6
Deferred compensation | 17.0 | 13.1
Non-performing loan interest | 1.2 | 1.1
Other real estate owned write-downs and carrying costs | 0.3 | 0.6
Tax credit carryforwards | 0.1 | 3.7
Net operating loss carryforwards | 3.9 | 8.7
Other | 0.1 | 3.1
Deferred tax assets | 58.2 | 60.6
Deferred tax liabilities: |  |
Fixed assets, principally differences in bases and depreciation | (6.9) | (6.7)
Deferred loan costs | (2.6) | (1.7)
Investment in joint venture partnership, principally due to differences in depreciation of partnership assets | (0.8) | (0.8)
Prepaid amounts | (0.6) | (0.6)
Government agency stock dividends | (1.5) | (1.6)
Goodwill and core deposit intangibles | (44.2) | (38.1)
Mortgage servicing rights | (6.4) | (5.7)
Other | (3.8) | (1.4)
Deferred tax liabilities | (66.8) | (56.6)
Net deferred tax assets (liabilities) |  | $ 4.0
Net deferred tax assets (liabilities) | (8.6) |
Federal |  |
Operating Loss Carryforwards [Line Items] |  |
Federal tax credit carryforwards | 0.1 |
Net operating loss carryforwards | $ 5.4 |

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