Loans and Allowance for Loan Losses - Investment in Nonaccrual Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Recorded investment in nonaccrual and loans past due over 90 days
Nonaccrual	$ 1,270	$ 1,298
Residential Real Estate
Recorded investment in nonaccrual and loans past due over 90 days
Nonaccrual	87	96
Other | Commercial Real Estate
Recorded investment in nonaccrual and loans past due over 90 days
Nonaccrual	$ 1,183	$ 1,202