Securities Held to Maturity - Amortized Cost and Estimated Fair Value of Held-to-maturity Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 35,827	$ 39,476
Gross Unrealized Gains	331	153
Gross Unrealized Losses	462	1,060
Fair Value	35,696	38,569
U.S. Government Agencies
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	6,000	8,000
Gross Unrealized Gains	13	11
Gross Unrealized Losses	0	18
Fair Value	6,013	7,993
Mortgage-backed Securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	22,451	23,936
Gross Unrealized Gains	300	142
Gross Unrealized Losses	37	299
Fair Value	22,714	23,779
Corporate Bonds
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	6,500	6,500
Gross Unrealized Gains	2	0
Gross Unrealized Losses	425	736
Fair Value	6,077	5,764
State and Political Subdivisions
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	876	1,040
Gross Unrealized Gains	16	0
Gross Unrealized Losses	0	7
Fair Value	$ 892	$ 1,033