v3.8.0.1
Allowance for Loan Losses - Bank's Allowance for Loan Losses (Details) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2017
Sep. 30, 2016
Sep. 30, 2017
Sep. 30, 2016
Dec. 31, 2016
Financing Receivable Allowance For Credit Losses [Line Items]          
Beginning Balance $ 16,800   $ 15,400 $ 10,600 $ 10,600
Provision for loan losses 701 $ 1,231 1,862 2,881 4,681
Charge-offs         (50)
Recoveries (1)   238   169
Ending Balance 17,500   17,500   15,400
Residential Properties          
Financing Receivable Allowance For Credit Losses [Line Items]          
Beginning Balance 8,851   6,669 6,799 6,799
Provision for loan losses 469   2,651   (130)
Ending Balance 9,320   9,320   6,669
Commercial Real Estate          
Financing Receivable Allowance For Credit Losses [Line Items]          
Beginning Balance 3,285   2,983 1,813 1,813
Provision for loan losses 281   583   1,051
Charge-offs         (50)
Recoveries         169
Ending Balance 3,566   3,566   2,983
Land and Construction          
Financing Receivable Allowance For Credit Losses [Line Items]          
Beginning Balance 287   233 103 103
Provision for loan losses 66   120   130
Ending Balance 353   353   233
Commercial and Industrial Loans          
Financing Receivable Allowance For Credit Losses [Line Items]          
Beginning Balance 4,093   5,227 1,649 1,649
Provision for loan losses (119)   (1,492)   3,578
Recoveries (1)   238    
Ending Balance 3,973   3,973   5,227
Consumer Loans          
Financing Receivable Allowance For Credit Losses [Line Items]          
Beginning Balance 284   288 $ 236 236
Provision for loan losses 4       52
Ending Balance $ 288   $ 288   $ 288