Securities Held to Maturity - Held-to-maturity Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Amortized Cost
Amortized Cost	$ 35,827	$ 39,476
Fair Value
Fair Value	35,696	38,569
U.S. Government Agencies
Amortized Cost
Due within one year	0
Due after one year through five years	0
Due after five through ten years	3,000
Due thereafter	3,000
Amortized Cost	6,000	8,000
Fair Value
Due within one year	0
Due after one year through five years	0
Due after five through ten years	3,011
Due thereafter	3,002
Fair Value	6,013	7,993
Mortgage-backed Securities
Amortized Cost
Due within one year	1,151
Due after one year through five years	11,370
Due after five through ten years	2,580
Due thereafter	7,350
Amortized Cost	22,451	23,936
Fair Value
Due within one year	1,153
Due after one year through five years	11,552
Due after five through ten years	2,565
Due thereafter	7,444
Fair Value	22,714	23,779
Corporate Bonds
Amortized Cost
Due within one year	1,500
Due after one year through five years	0
Due after five through ten years	1,000
Due thereafter	4,000
Amortized Cost	6,500	6,500
Fair Value
Due within one year	1,502
Due after one year through five years	0
Due after five through ten years	956
Due thereafter	3,619
Fair Value	6,077	5,764
State and Political Subdivisions
Amortized Cost
Due within one year	171
Due after one year through five years	705
Due after five through ten years	0
Amortized Cost	876	1,040
Fair Value
Due within one year	171
Due after one year through five years	721
Due after five through ten years	0
Fair Value	$ 892	$ 1,033