|**Other Long-term Debt (Tables)**  | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                        
|---------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
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|**Debt Disclosure [Abstract]**     |                                                                                                                                                                                                                                                                                                                                                                                                                                                        
|Summary of Other Long-Term Debt    | Other long-term debt at December 31 follows:20132012AmountWeightedAverageContractualRateWeightedAverageEffectiveRateAmountWeightedAverageContractualRateWeightedAverageEffectiveRate(dollars in thousands)Borrowings from FHLB due:2013$30,0852.32%2.32%2014$57,8921.13%1.13%57,8901.131.13201579,9710.820.8279,9700.820.8220163894.644.643874.644.6420174074.644.644054.644.6420184264.644.64Thereafter5,3004.664.665,7344.664.66Total$144,385$174,471
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|                                   |                                                                                                                                                                                                                                                                                                                                                                                                                                                        
|                                   | 2013                                                                                                                                                                                                                                                                                                                                                                                                                                                   
|                                   | Amount                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|                                   | (dollars in thousands)                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Borrowings from FHLB due:          |                                                                                                                                                                                                                                                                                                                                                                                                                                                        
|2013                               |                                                                                                                                                                                                                                                                                                                                                                                                                                                        
|2014                               | $                                                                                                                                                                                                                                                                                                                                                                                                                                                      
|2015                               | 79,971                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|2016                               | 389                                                                                                                                                                                                                                                                                                                                                                                                                                                    
|2017                               | 407                                                                                                                                                                                                                                                                                                                                                                                                                                                    
|2018                               | 426                                                                                                                                                                                                                                                                                                                                                                                                                                                    
|Thereafter                         | 5,300                                                                                                                                                                                                                                                                                                                                                                                                                                                  
|Total                              | $                                                                                                                                                                                                                                                                                                                                                                                                                                                      
|Summary of Scheduled Loan Payments | Scheduled loan payments for other long-term debt are summarized below:20142015201620172018ThereafterTotal(dollars in thousands)Long-term debt payments$57,854$79,971$389$407$426$5,300$144,347Purchase valuation amortization38—————38Total$57,892$79,971$389$407$426$5,300$144,385                                                                                                                                                                    
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|                                   |                                                                                                                                                                                                                                                                                                                                                                                                                                                        
|                                   | 2014                                                                                                                                                                                                                                                                                                                                                                                                                                                   
|                                   | (dollars in thousands)                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Long-term debt payments            | $                                                                                                                                                                                                                                                                                                                                                                                                                                                      
|Purchase valuation amortization    | 38                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Total                              | $                                                                                                                                                                                                                                                                                                                                                                                                                                                      

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