Investment Securities - Amortized Cost and Fair Value by Contractual Maturity (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Amortized Cost
Due in one year or less	$ 8,962
Due after one year through five years	36,227
Due after five years through ten years	10,910
Due after ten years	9,994
Total	66,093
Mortgage-backed securities	115,261
Total available-for-sale securities	181,354	$ 222,578
Fair Value
Due in one year or less	8,951
Due after one year through five years	36,256
Due after five years through ten years	10,926
Due after ten years	9,903
Total	66,036
Mortgage-backed securities	115,234
Total available-for-sale securities	$ 181,270	$ 218,205