Fair Values of Financial Instruments - Financial Instruments Not Disclosed Elsewhere (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Carrying Amount
Financial assets:
Loans, net	$ 626,607	$ 625,513
Financial liabilities:
Interest-bearing deposits	660,401	614,926
FHLB advances and notes payable	55,495	56,989
Estimated Fair Value
Financial assets:
Loans, net	612,003	604,290
Financial liabilities:
Interest-bearing deposits	629,813	570,509
FHLB advances and notes payable	56,065	56,979
Estimated Fair Value | Level 2
Financial liabilities:
Interest-bearing deposits	629,813	570,509
FHLB advances and notes payable	56,065	56,979
Estimated Fair Value | Level 3
Financial assets:
Loans, net	$ 612,003	$ 604,290