Loans - Aging of Past Due Loans by Class of Loans - Tabular Disclosure (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Aging of Past Due Loans by Class of Loans
Total Past Due	$ 12,466	$ 5,754
Loans Not Past Due	1,438,335	1,353,704
Total loan balance	1,450,801	1,359,458
30-59 Days Past Due
Aging of Past Due Loans by Class of Loans
Total Past Due	8,404	3,504
60-89 Days Past Due
Aging of Past Due Loans by Class of Loans
Total Past Due	3,860	262
90 Days or Greater Past Due
Aging of Past Due Loans by Class of Loans
Total Past Due	202	1,988
Commercial
Aging of Past Due Loans by Class of Loans
Total Past Due	10,118	5,251
Loans Not Past Due	596,163	551,271
Total loan balance	606,281	556,522
Commercial | 30-59 Days Past Due
Aging of Past Due Loans by Class of Loans
Total Past Due	6,258	3,285
Commercial | 60-89 Days Past Due
Aging of Past Due Loans by Class of Loans
Total Past Due	3,860	262
Commercial | 90 Days or Greater Past Due
Aging of Past Due Loans by Class of Loans
Total Past Due		1,704
Real estate
Aging of Past Due Loans by Class of Loans
Total loan balance	826,192	786,926
Consumer
Aging of Past Due Loans by Class of Loans
Loans Not Past Due	18,328	16,010
Total loan balance	18,328	16,010
Commercial | Real estate
Aging of Past Due Loans by Class of Loans
Total Past Due	1,872
Loans Not Past Due	610,158	625,665
Total loan balance	612,030	625,665
Commercial | Real estate | 30-59 Days Past Due
Aging of Past Due Loans by Class of Loans
Total Past Due	1,872
Land and construction | Real estate
Aging of Past Due Loans by Class of Loans
Total Past Due	201	219
Loans Not Past Due	88,170	84,209
Total loan balance	88,371	84,428
Land and construction | Real estate | 30-59 Days Past Due
Aging of Past Due Loans by Class of Loans
Total Past Due		219
Land and construction | Real estate | 90 Days or Greater Past Due
Aging of Past Due Loans by Class of Loans
Total Past Due	201
Home equity | Real estate
Aging of Past Due Loans by Class of Loans
Total Past Due	275	284
Loans Not Past Due	76,261	76,549
Total loan balance	76,536	76,833
Home equity | Real estate | 30-59 Days Past Due
Aging of Past Due Loans by Class of Loans
Total Past Due	274
Home equity | Real estate | 90 Days or Greater Past Due
Aging of Past Due Loans by Class of Loans
Total Past Due	1	$ 284
Residential mortgages | Real estate
Aging of Past Due Loans by Class of Loans
Loans Not Past Due	49,255
Total loan balance	$ 49,255