| Securities (Tables)
 | 3 Months Ended | 
      
        | Mar. 31, 2013 | 
      
        | Investments, Debt and Equity Securities [Abstract] |  | 
      
        | Available-for-sale Securities [Table Text Block] | The fair value of available-for-sale securities and the related gross unrealized gains and losses recognized in accumulated other comprehensive income (loss) were as follows:   
|  |  |  |  |  | Gross |  |  | Gross |  |  | Estimated |  |  
| (Dollars in thousands) |  | Cost |  |  | Unrealized |  |  | Unrealized |  |  | Fair |  |  
|  |  | Basis |  |  | Gains |  |  | Losses |  |  | Value |  |  
| March 31, 2013 |  |  |  |  |  |  |  |  |  |  |  |  |  
| U.S. government sponsored entities |  | $ | 22,495 |  |  | $ | 70 |  |  | $ | (12 | ) |  | $ | 22,553 |  |  
| Collateralized mortgage obligations and |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
| residential mortgage-backed securities |  |  | 100,301 |  |  |  | 2,772 |  |  |  | (52 | ) |  |  | 103,021 |  |  
| Municipal securities |  |  | 59,899 |  |  |  | 3,531 |  |  |  | (129 | ) |  |  | 63,301 |  |  
| Collateralized debt obligations |  |  | 5,208 |  |  |  | - |  |  |  | (3,621 | ) |  |  | 1,587 |  |  
| Total securities available-for-sale |  | $ | 187,903 |  |  | $ | 6,373 |  |  | $ | (3,814 | ) |  | $ | 190,462 |  |  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
| December 31, 2012 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
| U.S. government sponsored entities |  | $ | 23,009 |  |  | $ | 94 |  |  | $ | (7 | ) |  | $ | 23,096 |  |  
| Collateralized mortgage obligations and |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
| residential mortgage-backed securities |  |  | 96,782 |  |  |  | 3,147 |  |  |  | (15 | ) |  |  | 99,914 |  |  
| Municipal securities |  |  | 58,946 |  |  |  | 4,155 |  |  |  | (28 | ) |  |  | 63,073 |  |  
| Collateralized debt obligations |  |  | 5,208 |  |  |  | - |  |  |  | (3,816 | ) |  |  | 1,392 |  |  
| Total securities available-for-sale |  | $ | 183,945 |  |  | $ | 7,396 |  |  | $ | (3,866 | ) |  | $ | 187,475 |  |  | 
      
        | Schedule of Contractual Maturities of Available-for-sale Debt Securities [Table Text Block] | The fair value of available-for-sale debt securities and carrying amount, if different, at March 31, 2013 by contractual maturity, were as follows. Securities not due at a single maturity date, primarily mortgage-backed securities, are shown separately.   
|  |  | Available-for-sale |  |  
| (Dollars in thousands) |  | Estimated |  |  |  |  |  
|  |  | Fair |  |  | Tax-Equivalent |  |  
| March 31, 2013 |  | Value |  |  | Yield (%) |  |  
| Due in one year or less |  | $ | 452 |  |  |  | 6.76 |  |  
| Due from one to five years |  |  | 16,582 |  |  |  | 2.70 |  |  
| Due from five to ten years |  |  | 36,756 |  |  |  | 4.39 |  |  
| Due over ten years |  |  | 33,651 |  |  |  | 4.67 |  |  
| Collateralized mortgage obligations and residential mortgage-backed securities |  |  | 103,021 |  |  |  | 2.80 |  |  
| Total |  | $ | 190,462 |  |  |  | 3.44 |  |  | 
      
        | Schedule of Realized Gain (Loss) [Table Text Block] | Sales of available-for-sale securities were as follows:   
|  |  | March 31, |  |  | March 31, |  |  
| (Dollars in thousands) |  | 2013 |  |  | 2012 |  |  
|  |  |  |  |  |  |  |  
| Proceeds |  | $ | 2,983 |  |  | $ | 7,961 |  |  
| Gross gains |  |  | 128 |  |  |  | 366 |  |  
| Gross losses |  |  | - |  |  |  | - |  |  | 
      
        | Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] | Accumulated other comprehensive income/(loss) balances, net of tax, related to available-for-sale securities, were as follows:   
| (Dollars in thousands) |  | Unrealized gain/(loss)
 |  |  
| Beginning balance, December 31, 2012 |  | $ | 2,284 |  |  
| Current period change |  |  | (635 | ) |  
| Ending balance, March 31, 2013 |  | $ | 1,649 |  |  | 
      
        | Unrealized Gain (Loss) on Investments [Table Text Block] | Securities with unrealized losses at March 31, 2013 and December 31, 2012 not recognized in income are as follows:   
|  |  | Less than 12 months |  |  | 12 months or longer |  |  | Total |  |  
|  |  | Estimated |  |  |  |  |  | Estimated |  |  |  |  |  | Estimated |  |  |  |  |  
| (Dollars in thousands) |  | Fair |  |  | Unrealized |  |  | Fair |  |  | Unrealized |  |  | Fair |  |  | Unrealized |  |  
|  |  | Value |  |  | Losses |  |  | Value |  |  | Losses |  |  | Value |  |  | Losses |  |  
| March 31, 2013 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
| U.S. government sponsored entities |  | $ | 3,487 |  |  | $ | (12 | ) |  | $ | - |  |  | $ | - |  |  | $ | 3,487 |  |  | $ | (12 | ) |  
| Collateralized mortgage obligations and |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
| residential mortgage-backed securities |  |  | 6,516 |  |  |  | (52 | ) |  |  | - |  |  |  | - |  |  |  | 6,516 |  |  |  | (52 | ) |  
| Municipal securities |  |  | 5,804 |  |  |  | (129 | ) |  |  | - |  |  |  | - |  |  |  | 5,804 |  |  |  | (129 | ) |  
| Collateralized debt obligations |  |  | - |  |  |  | - |  |  |  | 1,587 |  |  |  | (3,621 | ) |  |  | 1,587 |  |  |  | (3,621 | ) |  
| Total temporarily impaired |  | $ | 15,807 |  |  | $ | (193 | ) |  | $ | 1,587 |  |  | $ | (3,621 | ) |  | $ | 17,394 |  |  | $ | (3,814 | ) |  
| Number of securities |  |  |  |  |  |  | 23 |  |  |  |  |  |  |  | 4 |  |  |  |  |  |  |  | 27 |  |    
|  |  | Less than 12 months |  |  | 12 months or longer |  |  | Total |  |  
|  |  | Estimated |  |  |  |  |  | Estimated |  |  |  |  |  | Estimated |  |  |  |  |  
| (Dollars in thousands) |  | Fair |  |  | Unrealized |  |  | Fair |  |  | Unrealized |  |  | Fair |  |  | Unrealized |  |  
|  |  | Value |  |  | Losses |  |  | Value |  |  | Losses |  |  | Value |  |  | Losses |  |  
| December 31, 2012 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
| U.S. government sponsored entities |  | $ | 3,492 |  |  | $ | (7 | ) |  | $ | - |  |  | $ | - |  |  | $ | 3,492 |  |  | $ | (7 | ) |  
| Collateralized mortgage obligations and |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
| residential mortgage-backed securities |  |  | 2,294 |  |  |  | (15 | ) |  |  | - |  |  |  | - |  |  |  | 2,294 |  |  |  | (15 | ) |  
| Municipal securities |  |  | 3,330 |  |  |  | (28 | ) |  |  | - |  |  |  | - |  |  |  | 3,330 |  |  |  | (28 | ) |  
| Collateralized debt obligations |  |  | - |  |  |  | - |  |  |  | 1,392 |  |  |  | (3,816 | ) |  |  | 1,392 |  |  |  | (3,816 | ) |  
| Total temporarily impaired |  | $ | 9,116 |  |  | $ | (50 | ) |  | $ | 1,392 |  |  | $ | (3,816 | ) |  | $ | 10,508 |  |  | $ | (3,866 | ) |  
| Number of securities |  |  |  |  |  |  | 14 |  |  |  |  |  |  |  | 4 |  |  |  |  |  |  |  | 18 |  |  |