Allowance for Loan Losses Allowance for Loan Loss Individually and Collectively Evaluated by Portfolio Segment (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Financing Receivable, Allowance for Credit Losses [Line Items]        
Individually evaluated for impairment $ 4,427 $ 7,124    
Collectively evaluated for impairment 20,308 22,951    
Acquired with deteriorated credit quality 715 3,609    
Total allowance for loan losses 25,450 33,684 33,982 27,956
Individually evaluated for impairment 55,119 58,096    
Collectively evaluated for impairment 2,160,903 1,773,065    
Acquired with deteriorated credit quality 37,284 61,876    
Total loans 2,253,306 1,893,037    
Commercial        
Financing Receivable, Allowance for Credit Losses [Line Items]        
Individually evaluated for impairment 2,633 4,644    
Collectively evaluated for impairment 10,334 12,704    
Acquired with deteriorated credit quality 0 0    
Total allowance for loan losses 12,967 17,348 13,965 9,183
Individually evaluated for impairment 40,073 39,527    
Collectively evaluated for impairment 595,833 586,215    
Acquired with deteriorated credit quality 23,005 40,060    
Total loans 658,911 665,802    
Construction        
Financing Receivable, Allowance for Credit Losses [Line Items]        
Individually evaluated for impairment 278 625    
Collectively evaluated for impairment 1,208 1,419    
Acquired with deteriorated credit quality 0 0    
Total allowance for loan losses 1,486 2,044 7,578 8,262
Individually evaluated for impairment 7,476 11,766    
Collectively evaluated for impairment 112,652 81,163    
Acquired with deteriorated credit quality 3,866 8,769    
Total loans 123,994 101,698    
Consumer        
Financing Receivable, Allowance for Credit Losses [Line Items]        
Individually evaluated for impairment 305 315    
Collectively evaluated for impairment 5,995 6,095    
Acquired with deteriorated credit quality 0 0    
Total allowance for loan losses 6,300 6,410 6,135 6,040
Individually evaluated for impairment 2,365 2,963    
Collectively evaluated for impairment 1,228,333 984,572    
Acquired with deteriorated credit quality 1,906 3,050    
Total loans 1,232,604 990,585    
Mortgage        
Financing Receivable, Allowance for Credit Losses [Line Items]        
Individually evaluated for impairment 1,211 1,540    
Collectively evaluated for impairment 2,040 1,836    
Acquired with deteriorated credit quality 0 0    
Total allowance for loan losses 3,251 3,376 3,122 2,535
Individually evaluated for impairment 5,205 3,840    
Collectively evaluated for impairment 224,085 121,115    
Acquired with deteriorated credit quality 8,507 9,997    
Total loans 237,797 134,952    
Acquired, Covered and Non-covered        
Financing Receivable, Allowance for Credit Losses [Line Items]        
Individually evaluated for impairment 0 0    
Collectively evaluated for impairment 0 0    
Acquired with deteriorated credit quality 715 3,609    
Total allowance for loan losses 715 3,609    
Individually evaluated for impairment 0 0    
Collectively evaluated for impairment 0 0    
Acquired with deteriorated credit quality 0 0    
Total loans 0 0    
Unallocated        
Financing Receivable, Allowance for Credit Losses [Line Items]        
Individually evaluated for impairment 0 0    
Collectively evaluated for impairment 731 897    
Acquired with deteriorated credit quality 0 0    
Total allowance for loan losses 731 897 1,030 1,936
Individually evaluated for impairment 0 0    
Collectively evaluated for impairment 0 0    
Acquired with deteriorated credit quality 0 0    
Total loans $ 0 $ 0