Securities (Tables)
 12 Months Ended
Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]  
Schedule of available for sale securities

 Available-for-Sale Securities
The following tables summarize available-for-sale securities held by the Company at December 31, 2014 and 2013:
 
  Available-for-Sale Securities
 December 31, 2014  Amortized Cost   Gross Unrealized Gains  Gross Unrealized Losses  Fair Value
 (in thousands)            
 Obligations of U.S. Government sponsored entities  $553,300   $6,222   $1,702   $557,820 
 Obligations of U.S. states and political subdivisions   70,790    999    279    71,510 
 Mortgage-backed securities – residential, issued by                    
U.S. Government agencies   108,931    2,339    1,344    109,926 
U.S. Government sponsored entities   660,195    7,309    8,384    659,120 
Non-U.S. Government agencies or sponsored entities   267    4    0    271 
 U.S. corporate debt securities   2,500    0    338    2,162 
 Total debt securities   1,395,983    16,873    12,047    1,400,809 
 Equity securities   1,475    0    48    1,427 
 Total available-for-sale securities  $1,397,458   $16,873   $12,095   $1,402,236 

  

   Available-for-Sale Securities
 December 31, 2013  Amortized Cost   Gross Unrealized Gains  Gross Unrealized Losses  Fair Value
 (in thousands)            
 Obligations of U.S. Government sponsored entities   558,130    7,720    9,505    556,345 
 Obligations of U.S. states and political subdivisions   68,216    1,193    1,447    67,962 
 Mortgage-backed securities – residential, issued by                    
U.S. Government agencies   147,766    2,554    3,642    146,678 
U.S. Government sponsored entities   587,843    8,122    18,493    577,472 
Non-U.S. Government agencies or sponsored entities   306    5    0    311 
 U.S. corporate debt securities   5,000    8    375    4,633 
 Total debt securities   1,367,261    19,602    33,462    1,353,401 
 Equity securities   1,475    0    65    1,410 
 Total available-for-sale securities  $1,368,736   $19,602   $33,527   $1,354,811 

 
Schedule of held to maturity securities
The following tables summarize held-to-maturity securities held by the Company at December 31, 2014 and 2013:
                 
    Held-to-Maturity Securities
December 31, 2014   Amortized Cost   Gross Unrealized Gains   Gross Unrealized Losses   Fair Value
(in thousands)                
Obligations of U.S. Government sponsored entities   $ 71,906     $ 400     $ 37     $ 72,269  
Obligations of U.S. states and political subdivisions     16,262       505       0       16,767  
Total held-to-maturity debt securities   $ 88,168     $ 905     $ 37     $ 89,036  
                                 

 

  

Held-to-Maturity Securities                
    Held-to-Maturity Securities
December 31, 2013   Amortized Cost   Gross Unrealized Gains   Gross Unrealized Losses   Fair Value
(in thousands)                
Obligations of U.S. states and political subdivisions   $ 18,980     $ 645     $ 0     $ 19,625  
Total held-to-maturity debt securities   $ 18,980     $ 645     $ 0     $ 19,625  

 
Schedule available for sale securities with unrealized losses
The following table sets forth information with regard to sales transactions of securities available-for-sale:
 
    Year ended December 31,
(in thousands)   2014   2013   2012
Proceeds from sales   $ 90,551     $ 115,796     $ 217,971  
Gross realized gains     426       762       1,268  
Gross realized losses     (78 )     (163 )     (944 )
Net gains on sales of available-for-sale securities   $ 348     $ 599     $ 324  

 

There were no sales of held-to-maturity securities in 2014, 2013 and 2012.

  

The following table summarizes available-for-sale securities that had unrealized losses at December 31, 2014:
 
December 31, 2014                        
Available-for-Sale Securities   Less than 12 Months   12 Months or Longer   Total
(in thousands)   Fair Value   Unrealized Losses   Fair Value   Unrealized Losses   Fair Value   Unrealized Losses
Obligations of U.S. Government                        
sponsored entities   $ 71,363     $ 385     $ 65,497     $ 1,317     $ 136,860     $ 1,702  
Obligations of U.S. states and political                                                
subdivisions     15,451       124       8,102       155       23,553       279  
Mortgage-backed securities – residential,                                                
issued by                                                
U.S. Government agencies     2,623       21       28,502       1,323       31,125       1,344  
U.S. Government sponsored entities     162,377       719       271,503       7,665       433,880       8,384  
U.S. corporate debt securities     0       0       2,163       338       2,163       338  
Equity Securities     0       0       952       48       952       48  
Total available-for-sale securities   $ 251,814     $ 1,249     $ 376,719     $ 10,846     $ 628,533     $ 12,095
Schedule held-to-maturity securities with unrealized losses
The following table summarizes held-to-maturity securities that had unrealized losses at December 31, 2014:
 
Held-to-Maturity Securities   Less than 12 Months   12 Months or Longer   Total
(in thousands)   Fair Value   Unrealized Losses   Fair Value   Unrealized Losses   Fair Value   Unrealized Losses
Obligations of U.S. sponsored entities   $ 15,095     $ 37     $ 0     $ 0     $ 15,095     $ 37  
Total held-to-maturity securities   $ 15,095     $ 37     $ 0     $ 0     $ 15,095     $ 37  

 

The following table summarizes available-for-sale securities that had unrealized losses at December 31, 2013:
 
December 31, 2013                        
Available-for-Sale Securities   Less than 12 Months 12 Months or Longer   Total
(in thousands)   Fair Value   Unrealized Losses   Fair Value   Unrealized Losses   Fair Value   Unrealized Losses
Obligations of U.S. Government                        
sponsored entities   $ 337,967     $ 9,467     $ 1,761     $ 38     $ 339,728     $ 9,505  
Obligations of U.S. states and political                                                
subdivisions     21,821       821       6,173       626       27,994       1,447  
Mortgage-backed securities – residential,                                                
issued by                                                
U.S. Government agencies     70,052       2,701       14,874       941       84,926       3,642  
U.S. Government sponsored entities     293,945       14,061       76,070       4,432       370,015       18,493  
U.S. corporate debt securities     0       0       2,125       375       2,125       375  
Equity securities     0       0       935       65       935       65  
Total available-for-sale securities   $ 723,785     $ 27,050     $ 101,938     $ 6,477     $ 825,723     $ 33,527
Schedule of rollforward of credit losses on debt securities for which portion of OTTI is recognized in OCI
The following table summarizes the roll-forward of credit losses on debt securities held by the Company for which a portion of an other-than-temporary impairment is recognized in other comprehensive income:
    As of December 31,
(in thousands)   2014   2013   2012
Credit losses at beginning of the period   $ 0     $ 441     $ 245  
Credit losses related to securities for which an other-than-                        
Credit losses related to securities for which an other-than-                        
temporary impairment was recognized     0       0       196  
Sales of securities for which an other-than-temporary impairment                        
was previously recognized     0       (441 )     0  
Ending balance of credit losses on debt securities held for                        
which a portion of an other-than-temporary impairment                        
was recognized in other comprehensive income   $ 0     $ 0     $ 441  

 
Schedule of amortized cost and estimated fair value of debt securities by contractual maturity

The amortized cost and estimated fair value of debt securities by contractual maturity are shown in the following table. Expected maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations with or without call or prepayment penalties. Mortgage-backed securities are shown separately since they are not due at a single maturity date.

           
 December 31, 2014   Amortized   Fair  
 (in thousands)   Cost   Value  
 Available-for-sale securities:          
  Due in one year or less $  67,281 $  68,350   
  Due after one year through five years    342,548    347,230   
  Due after five years through ten years    199,724    199,276   
  Due after ten years    17,037    16,636   
 Total    626,590    631,492   
  Mortgage-backed securities    769,393    769,317   
 Total available-for-sale debt securities $  1,395,983 $  1,400,809   

           
 December 31, 2013   Amortized   Fair  
 (in thousands)   Cost   Value  
 Available-for-sale securities:          
  Due in one year or less $  25,596  $  26,017   
  Due after one year through five years    263,553    271,303   
  Due after five years through ten years    313,245    304,414   
  Due after ten years    28,952    27,206   
 Total    631,346    628,940   
  Mortgage-backed securities    735,915    724,461   
 Total available-for-sale debt securities $  1,367,261  $  1,353,401   

           
December 31, 2014   Amortized   Fair  
(in thousands)   Cost   Value  
Held-to-maturity securities:          
  Due in one year or less $  11,400  $  11,471   
  Due after one year through five years    3,440     3,694   
  Due after five years through ten years    73,020     73,518   
  Due after ten years    308     353   
Total held-to-maturity debt securities $  88,168  $  89,036   

 

           
December 31, 2013   Amortized   Fair  
(in thousands)   Cost   Value  
Held-to-maturity securities:          
  Due in one year or less $  10,952  $  11,021   
  Due after one year through five years    5,636     6,004   
  Due after five years through ten years    1,878     2,051   
  Due after ten years    514     549   
Total held-to-maturity debt securities $  18,980  $  19,625   

 
Schedule of trading securities at estimated fair value

 

 
The following summarizes trading securities, at estimated fair value, as of:  
   
(in thousands)   December 31, 2014   December 31, 2013  
             
Obligations of U.S. Government sponsored entities $  7,404  $  8,275   
Mortgage-backed securities – residential, issued by          
  U.S. Government sponsored entities    1,588     2,716   
Total trading securities $  8,992  $  10,991