Securities (Details 5) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2013
Dec. 31, 2012
Available For Sale Securities, Amortized Cost    
Total $ 1,367,261 $ 1,347,358 [1]
Available For Sale Securities, Fair value    
Total 1,353,401 1,391,297
Total debt securities
    
Available For Sale Securities, Amortized Cost    
Due in one year or less 25,596 39,552 [1]
Due after one year through five years 263,553 355,296 [1]
Due after five years through ten years 313,245 255,795 [1]
Due after ten years 28,952 3,041 [1]
Total 631,346 653,684 [1]
Available For Sale Securities, Fair value    
Due in one year or less 26,017 39,990
Due after one year through five years 271,303 370,933
Due after five years through ten years 304,414 264,966
Due after ten years 27,206 3,032
Total 628,940 678,921
Mortgage-backed securities
    
Available For Sale Securities, Amortized Cost    
Total 735,915 693,674 [1]
Available For Sale Securities, Fair value    
Total $ 724,461 $ 712,376
[1] Net of other-than-temporary impairment losses recognized in earnings.