Investment Securities - Maturities (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Amortized cost
Due after one year through five years	$ 10,000
Due after five years through ten years	10,000
Due after ten years	9,275
Mortgage and asset-backed securities	209,429
Amortized cost	238,704	$ 274,957
Fair value
Due after one year through five years	10,058
Due after five years through ten years	10,000
Due after ten years	9,462
Mortgage and asset-backed securities	212,014
Fair value	$ 241,534	$ 277,439