|**Income Tax (Tables)**                                                                           | 6 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
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|**Income Tax Disclosure [Abstract]**                                                              |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
|Schedule of differences between income taxes at federal statutory tax rate and effective tax rate | The following table summarizes the major components creating differences between income taxes at the federal statutory and the effective tax rate recorded in the consolidated statements of income for thethree and six months ended June 30, 2020and2019:Three Months EndedJune 30,Six Months EndedJune 30,2020201920202019Reconciliation of Federal Statutory to Actual Tax Expense:Federal statutory income tax at 21%$7,899$10,249$15,827$19,858Tax-exempt interest income(3,199)(2,403)(6,221)(4,670)Share-based compensation(6)(41)(6)(391)Tax-exempt earnings and gains on life insurance(278)(199)(564)(406)Tax credits(89)(63)(150)(141)CARES Act - NOL carryback rate differential——(1,178)—Other296206405440Actual Tax Expense$4,623$7,749$8,113$14,690Effective Tax Rate12.3%15.9%10.8%15.5%
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|                                                                                                  | Three Months EndedJune 30,                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
|                                                                                                  | 2020                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Reconciliation of Federal Statutory to Actual Tax Expense:                                        |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
|Federal statutory income tax at 21%                                                               | $                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        
|Tax-exempt interest income                                                                        | (3,199                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
|Share-based compensation                                                                          | (6                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       
|Tax-exempt earnings and gains on life insurance                                                   | (278                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Tax credits                                                                                       | (89                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
|CARES Act - NOL carryback rate differential                                                       | —                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        
|Other                                                                                             | 296                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
|Actual Tax Expense                                                                                | $                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        
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|Effective Tax Rate                                                                                | 12.3                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     

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