|**Borrowings (Tables)**                       | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                       
|--------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|
|**Debt Disclosure [Abstract]**                |                                                                                                                                                                                                                                                                                                                                                                                                                                       
|Schedule of Debt                              | The following table summarizes the Corporation's borrowings as of December 31, 2017 and 2016:December 31, 2017December 31, 2016Federal funds purchased$144,038$120,349Securities sold under repurchase agreements136,623146,480Federal Home Loan Bank advances414,377298,923Subordinated debentures and term loans139,349128,445Total Borrowings$834,387$694,197                                                                      
|                                             
|                                              |                                                                                                                                                                                                                                                                                                                                                                                                                                       
|                                              | December 31, 2017                                                                                                                                                                                                                                                                                                                                                                                                                     
|Federal funds purchased                       | $                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Securities sold under repurchase agreements   | 136,623                                                                                                                                                                                                                                                                                                                                                                                                                               
|Federal Home Loan Bank advances               | 414,377                                                                                                                                                                                                                                                                                                                                                                                                                               
|Subordinated debentures and term loans        | 139,349                                                                                                                                                                                                                                                                                                                                                                                                                               
|Total Borrowings                              | $                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Schedule of Maturities of Long-term Debt      | Contractual maturities of borrowings as ofDecember 31, 2017, are as follows:Maturities in Years Ending December 31:Federal Funds PurchasedSecurities SoldUnder Repurchase AgreementsFederal HomeLoan BankAdvancesSubordinatedDebentures andTerm Loans2018$144,038$136,623$171,3912019121,713202041,273202125,000202220,000After 202235,000$143,430ASC 805 fair value adjustments at acquisition(4,081)$144,038$136,623$414,377$139,349
|                                             
|                                              |                                                                                                                                                                                                                                                                                                                                                                                                                                       
|Maturities in Years Ending December 31:       | Federal Funds Purchased                                                                                                                                                                                                                                                                                                                                                                                                               
|2018                                          | $                                                                                                                                                                                                                                                                                                                                                                                                                                     
|2019                                          |                                                                                                                                                                                                                                                                                                                                                                                                                                       
|2020                                          |                                                                                                                                                                                                                                                                                                                                                                                                                                       
|2021                                          |                                                                                                                                                                                                                                                                                                                                                                                                                                       
|2022                                          |                                                                                                                                                                                                                                                                                                                                                                                                                                       
|After 2022                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                       
|ASC 805 fair value adjustments at acquisition |                                                                                                                                                                                                                                                                                                                                                                                                                                       
|                                              | $                                                                                                                                                                                                                                                                                                                                                                                                                                     

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