v3.8.0.1
Allowance for Loan Losses - Risk Category of Loans by Class of Loans (Details) - USD ($)
$ in Thousands
Dec. 31, 2017
Dec. 31, 2016
Accounts Notes And Loans Receivable [Line Items]    
Total loans $ 3,655,262 $ 2,552,016
Residential Properties    
Accounts Notes And Loans Receivable [Line Items]    
Total loans 2,581,245 1,780,889
Commercial Real Estate    
Accounts Notes And Loans Receivable [Line Items]    
Total loans 696,748 476,959
Commercial and Industrial Loans    
Accounts Notes And Loans Receivable [Line Items]    
Total loans 310,779 237,941
Consumer Loans    
Accounts Notes And Loans Receivable [Line Items]    
Total loans 29,330 32,127
Land    
Accounts Notes And Loans Receivable [Line Items]    
Total loans 37,160 24,100
Pass    
Accounts Notes And Loans Receivable [Line Items]    
Total loans 3,623,281 2,519,683
Pass | Residential Properties    
Accounts Notes And Loans Receivable [Line Items]    
Total loans 2,578,773 1,773,296
Pass | Commercial Real Estate    
Accounts Notes And Loans Receivable [Line Items]    
Total loans 680,449 470,484
Pass | Commercial and Industrial Loans    
Accounts Notes And Loans Receivable [Line Items]    
Total loans 298,408 219,676
Pass | Consumer Loans    
Accounts Notes And Loans Receivable [Line Items]    
Total loans 29,330 32,127
Pass | Land    
Accounts Notes And Loans Receivable [Line Items]    
Total loans 36,321 24,100
Special Mention    
Accounts Notes And Loans Receivable [Line Items]    
Total loans 7,383 7,038
Special Mention | Residential Properties    
Accounts Notes And Loans Receivable [Line Items]    
Total loans 192 1,500
Special Mention | Commercial Real Estate    
Accounts Notes And Loans Receivable [Line Items]    
Total loans 6,326 1,913
Special Mention | Commercial and Industrial Loans    
Accounts Notes And Loans Receivable [Line Items]    
Total loans 865 3,625
Substandard    
Accounts Notes And Loans Receivable [Line Items]    
Total loans 11,162 16,301
Substandard | Residential Properties    
Accounts Notes And Loans Receivable [Line Items]    
Total loans 2,280  
Substandard | Commercial Real Estate    
Accounts Notes And Loans Receivable [Line Items]    
Total loans 5,936 2,414
Substandard | Commercial and Industrial Loans    
Accounts Notes And Loans Receivable [Line Items]    
Total loans 2,107 13,887
Substandard | Land    
Accounts Notes And Loans Receivable [Line Items]    
Total loans 839  
Impaired    
Accounts Notes And Loans Receivable [Line Items]    
Total loans 13,436 8,994
Impaired | Residential Properties    
Accounts Notes And Loans Receivable [Line Items]    
Total loans   6,093
Impaired | Commercial Real Estate    
Accounts Notes And Loans Receivable [Line Items]    
Total loans 4,037 2,148
Impaired | Commercial and Industrial Loans    
Accounts Notes And Loans Receivable [Line Items]    
Total loans $ 9,399 $ 753