Allowance for Loan Losses Summary of Changes in the Allowance for Loan Losses, by Loan Portfolio Segment (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Financing Receivable, Allowance for Credit Losses [Roll Forward]      
Beginning balance $ 33,684 $ 33,982 $ 27,956
Charge-offs (11,144) (10,080) (12,326)
Recoveries 4,438 3,165 1,953
Net (charge-offs)/recoveries (6,706) (6,915) (10,373)
Decrease in FDIC indemnification asset (2,059)    
Increase in FDIC indemnification asset   1,177 2,979
Provision for loan losses 531 5,440 13,420
Ending balance 25,450 33,684 33,982
Commercial      
Financing Receivable, Allowance for Credit Losses [Roll Forward]      
Beginning balance 17,348 13,965 9,183
Charge-offs (5,440) (3,820) (1,080)
Recoveries 33 425 61
Net (charge-offs)/recoveries (5,407) (3,395) (1,019)
Decrease in FDIC indemnification asset 0    
Increase in FDIC indemnification asset   0 0
Provision for loan losses 1,026 6,778 5,801
Ending balance 12,967 17,348 13,965
Construction      
Financing Receivable, Allowance for Credit Losses [Roll Forward]      
Beginning balance 2,044 7,578 8,262
Charge-offs (361) (303) (3,476)
Recoveries 2,219 682 678
Net (charge-offs)/recoveries 1,858 379 (2,798)
Decrease in FDIC indemnification asset 0    
Increase in FDIC indemnification asset   0 0
Provision for loan losses (2,416) (5,913) 2,114
Ending balance 1,486 2,044 7,578
Consumer      
Financing Receivable, Allowance for Credit Losses [Roll Forward]      
Beginning balance 6,410 6,135 6,040
Charge-offs (4,303) (4,993) (4,410)
Recoveries 1,424 1,757 1,193
Net (charge-offs)/recoveries (2,879) (3,236) (3,217)
Decrease in FDIC indemnification asset 0    
Increase in FDIC indemnification asset   0 0
Provision for loan losses 2,769 3,511 3,312
Ending balance 6,300 6,410 6,135
Mortgage      
Financing Receivable, Allowance for Credit Losses [Roll Forward]      
Beginning balance 3,376 3,122 2,535
Charge-offs (180) (634) (653)
Recoveries 76 106 21
Net (charge-offs)/recoveries (104) (528) (632)
Decrease in FDIC indemnification asset 0    
Increase in FDIC indemnification asset   0 0
Provision for loan losses (21) 782 1,219
Ending balance 3,251 3,376 3,122
Covered      
Financing Receivable, Allowance for Credit Losses [Roll Forward]      
Beginning balance 3,331 1,964 0
Charge-offs (766) (300) (2,630)
Recoveries 627 195 0
Net (charge-offs)/recoveries (139) (105) (2,630)
Decrease in FDIC indemnification asset (2,059)    
Increase in FDIC indemnification asset   1,177 2,979
Provision for loan losses (578) 295 1,615
Ending balance 555 3,331 1,964
Acquired, Non-covered      
Financing Receivable, Allowance for Credit Losses [Roll Forward]      
Beginning balance 278 188 0
Charge-offs (94) (30) (77)
Recoveries 59 0 0
Net (charge-offs)/recoveries (35) (30) (77)
Decrease in FDIC indemnification asset 0    
Increase in FDIC indemnification asset   0 0
Provision for loan losses (83) 120 265
Ending balance 160 278 188
Unallocated      
Financing Receivable, Allowance for Credit Losses [Roll Forward]      
Beginning balance 897 1,030 1,936
Charge-offs 0 0 0
Recoveries 0 0 0
Net (charge-offs)/recoveries 0 0 0
Decrease in FDIC indemnification asset 0    
Increase in FDIC indemnification asset   0 0
Provision for loan losses (166) (133) (906)
Ending balance $ 731 $ 897 $ 1,030