AFS Securities (AFS securities with gross unrealized losses) (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2013
Securities
Dec. 31, 2012
Securities
Available-for-sale securities with gross unrealized losses    
Gross Unrealized Losses, Less Than Twelve Months $ 8,457 $ 190
Fair Value, Less Than Twelve Months 251,760 30,518
Gross Unrealized Losses, Twelve Months or More 4,007 1,344
Fair Value, Twelve Months or More 33,161 8,493
Total Unrealized Losses 12,464 1,534
Number of Securities in an unrealized loss position, Less Than Twelve Months, Fair Value 182 15
Number of Securities in an unrealized loss position, Twelve Months or More, Fair Value 19 6
Number of Securities in an unrealized loss position, Total Unrealized Losses 201 21
Auction rate money market preferred [Member]
   
Available-for-sale securities with gross unrealized losses    
Gross Unrealized Losses, Less Than Twelve Months 0 0
Fair Value, Less Than Twelve Months 0 0
Gross Unrealized Losses, Twelve Months or More 623 422
Fair Value, Twelve Months or More 2,577 2,778
Total Unrealized Losses 623 422
Collateralized mortgage obligations [Member]
   
Available-for-sale securities with gross unrealized losses    
Gross Unrealized Losses, Less Than Twelve Months 2,345  
Fair Value, Less Than Twelve Months 84,478  
Gross Unrealized Losses, Twelve Months or More 0  
Fair Value, Twelve Months or More 0  
Total Unrealized Losses 2,345  
Government sponsored enterprises [Member]
   
Available-for-sale securities with gross unrealized losses    
Gross Unrealized Losses, Less Than Twelve Months 1,122  
Fair Value, Less Than Twelve Months 22,873  
Gross Unrealized Losses, Twelve Months or More 0  
Fair Value, Twelve Months or More 0  
Total Unrealized Losses 1,122  
States and political subdivisions [Member]
   
Available-for-sale securities with gross unrealized losses    
Gross Unrealized Losses, Less Than Twelve Months 2,566 80
Fair Value, Less Than Twelve Months 42,593 5,019
Gross Unrealized Losses, Twelve Months or More 981 485
Fair Value, Twelve Months or More 6,115 2,352
Total Unrealized Losses 3,547 565
Preferred stocks [Member]
   
Available-for-sale securities with gross unrealized losses    
Gross Unrealized Losses, Less Than Twelve Months 0 0
Fair Value, Less Than Twelve Months 0 0
Gross Unrealized Losses, Twelve Months or More 993 437
Fair Value, Twelve Months or More 2,807 3,363
Total Unrealized Losses 993 437
Mortgage-backed securities [Member]
   
Available-for-sale securities with gross unrealized losses    
Gross Unrealized Losses, Less Than Twelve Months 2,424 110
Fair Value, Less Than Twelve Months 101,816 25,499
Gross Unrealized Losses, Twelve Months or More 1,410 0
Fair Value, Twelve Months or More 21,662 0
Total Unrealized Losses $ 3,834 $ 110