Disclosures About Fair Value of Financial Instruments - Fair Value, Assets Measured on Recurring Basis (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Agency mortgage-backed securities
Recurring Assets, Fair Value Disclosure	$ 169,940,000	$ 165,042,000
Agency collateralized mortgage obligations
Recurring Assets, Fair Value Disclosure	176,621,000	151,950,000
States and political subdivisions securities
Recurring Assets, Fair Value Disclosure	47,325,000	35,125,000
Small Business Administration securities
Recurring Assets, Fair Value Disclosure	21,047,000	22,058,000
Interest Rate Derivative Asset
Recurring Assets, Fair Value Disclosure	5,062,000	31,476,000
Interest Rate Derivative Liability
Recurring Assets, Fair Value Disclosure	(5,454,000)	(1,547,000)
Fair Value, Inputs, Level 1
Securities at fair value	0	0
Fair Value, Inputs, Level 2 | Agency mortgage-backed securities
Recurring Assets, Fair Value Disclosure	169,940,000	165,042,000
Fair Value, Inputs, Level 2 | Agency collateralized mortgage obligations
Recurring Assets, Fair Value Disclosure	176,621,000	151,950,000
Fair Value, Inputs, Level 2 | States and political subdivisions securities
Recurring Assets, Fair Value Disclosure	47,325,000	35,125,000
Fair Value, Inputs, Level 2 | Small Business Administration securities
Recurring Assets, Fair Value Disclosure	21,047,000	22,058,000
Fair Value, Inputs, Level 2 | Interest Rate Derivative Asset
Recurring Assets, Fair Value Disclosure	5,062,000	31,476,000
Fair Value, Inputs, Level 2 | Interest Rate Derivative Liability
Recurring Assets, Fair Value Disclosure	(5,454,000)	(1,547,000)
Fair Value, Inputs, Level 3
Securities at fair value	$ 0	$ 0