Goodwill and Other Intangible Assets (Details 3) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2014
Dec. 31, 2013
Goodwill and other intangibles assets    
Net carrying amount $ 6,687 $ 9,571
Estimated amortization expense:    
Net carrying amount 6,687 9,571
Core deposit intangible assets    
Goodwill and other intangibles assets    
Gross carrying amount 19,962  
Accumulated amortization 15,708  
Net carrying amount 4,254 6,124
Estimated amortization expense:    
2015 1,719  
2016 1,644  
2017 891  
Net carrying amount 4,254 6,124
Customer relationship intangible assets    
Goodwill and other intangibles assets    
Gross carrying amount 11,320  
Accumulated amortization 8,887  
Net carrying amount 2,433 3,447
Estimated amortization expense:    
2015 972  
2016 929  
2017 532  
Net carrying amount $ 2,433 $ 3,447