v3.8.0.1
Loans - Summary of Delinquent and Nonaccrual Loans (Details) - USD ($)
$ in Thousands
Dec. 31, 2017
Dec. 31, 2016
Accounts Notes And Loans Receivable [Line Items]    
Total Past Due and Nonaccrual $ 13,546 $ 14,168
90 Days or More Past Due and Still Accruing 2,109 5,928
Nonaccrual Past Due and Still Accruing 11,359 8,238
Current 3,641,716 2,537,848
Total loans $ 3,655,262 $ 2,552,016
Percentage of Total Loans Due 30-59 Days 0.00%  
Percentage of Total Loans Due 60-89 Days   0.00%
Percentage of Total Loans Due 90 Days or More 0.06% 0.23%
Percentage of Total Loans Due Nonaccrual 0.31% 0.32%
Percentage of Total Loans 0.37% 0.56%
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 Past Due and Nonaccrual 10,406 7,161
90 Days or More Past Due and Still Accruing 789 3,800
Nonaccrual Past Due and Still Accruing 9,617 3,359
Current 300,373 230,780
Total loans 310,779 237,941
Consumer Loans    
Accounts Notes And Loans Receivable [Line Items]    
Current 29,330 32,127
Total loans 29,330 32,127
Land    
Accounts Notes And Loans Receivable [Line Items]    
Total loans 37,160 24,100
30-59 Days    
Accounts Notes And Loans Receivable [Line Items]    
Total Past Due and Nonaccrual 78  
60-89 Days    
Accounts Notes And Loans Receivable [Line Items]    
Total Past Due and Nonaccrual   2
60-89 Days | Commercial and Industrial Loans    
Accounts Notes And Loans Receivable [Line Items]    
Total Past Due and Nonaccrual   2
Real Estate Loans    
Accounts Notes And Loans Receivable [Line Items]    
Total loans 3,315,153 2,281,948
Real Estate Loans | Residential Properties    
Accounts Notes And Loans Receivable [Line Items]    
Total Past Due and Nonaccrual 78 3,759
Nonaccrual Past Due and Still Accruing   3,759
Current 2,581,167 1,777,130
Total loans 2,581,245 1,780,889
Real Estate Loans | Commercial Real Estate    
Accounts Notes And Loans Receivable [Line Items]    
Total Past Due and Nonaccrual 3,062 3,248
90 Days or More Past Due and Still Accruing 1,320 2,128
Nonaccrual Past Due and Still Accruing 1,742 1,120
Current 693,686 473,711
Total loans 696,748 476,959
Real Estate Loans | Land    
Accounts Notes And Loans Receivable [Line Items]    
Current 37,160 24,100
Total loans 37,160 $ 24,100
Real Estate Loans | 30-59 Days | Residential Properties    
Accounts Notes And Loans Receivable [Line Items]    
Total Past Due and Nonaccrual $ 78