Securities - Amortized Cost and Estimated Fair Value by Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Available-for-sale Securities, Amortized Cost
Amortized Cost	$ 327,970	$ 317,528
Available-for-sale Securities, Estimated Fair Value
Total	317,520	315,580
Mortgage-backed Securities
Available-for-sale Securities, Amortized Cost
Due within one year	0	0
Due after one through five years	6,179	13,360
Due after five through ten years	7,077	6,261
Due after ten years	139,094	148,450
Amortized Cost	152,350	168,071
Available-for-sale Securities, Estimated Fair Value
Due within one year	0	0
Due after one through five years	6,264	13,391
Due after five through ten years	7,404	6,257
Due after ten years	140,598	148,835
Total	154,266	168,483
Investment Securities
Available-for-sale Securities, Amortized Cost
Due within one year	0	0
Due after one through five years	3,040	2,043
Due after five through ten years	49,249	58,460
Due after ten years	123,331	88,954
Amortized Cost	175,620	149,457
Available-for-sale Securities, Estimated Fair Value
Due within one year	0	0
Due after one through five years	3,096	2,084
Due after five through ten years	44,707	57,680
Due after ten years	115,451	87,333
Total	$ 163,254	$ 147,097