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Summary of Significant Accounting Policies - Premises and Equipment (Details) - USD ($) $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2018 | Dec. 31, 2017
Transfers and Servicing of Financial Assets |  |
Mortgage loans serviced for others | $ 711.1 | $ 695.1
Buildings | Minimum |  |
Premises and equipment |  |
Useful lives | 25 years |
Buildings | Maximum |  |
Premises and equipment |  |
Useful lives | 40 years |
Building improvements | Minimum |  |
Premises and equipment |  |
Useful lives | 3 years |
Building improvements | Maximum |  |
Premises and equipment |  |
Useful lives | 15 years |
Furniture and equipment | Minimum |  |
Premises and equipment |  |
Useful lives | 3 years |
Furniture and equipment | Maximum |  |
Premises and equipment |  |
Useful lives | 10 years |

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- Definition Fair value as of the balance sheet date of mortgage loans representing net future revenues from contractually specified servicing fees, late charges, and other ancillary revenues, in excess of future costs related to servicing arrangements. + References No definition available. + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Definition Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment. + References No definition available. + Details
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- References No definition available. + Details
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- Details
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- Details
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- Details
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- Details
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- Details
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