6. Fair Value, Level of Hierarchy (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Estimated Fair Value	$ 184,428	$ 194,578
Level 1
Estimated Fair Value	0	0
Level 2
Estimated Fair Value	184,178	194,328
Level 3
Estimated Fair Value	250	250
Mortgage-backed securities
Estimated Fair Value	53,631	52,103
Mortgage-backed securities | Level 1
Estimated Fair Value	0	0
Mortgage-backed securities | Level 2
Estimated Fair Value	53,631	52,103
Mortgage-backed securities | Level 3
Estimated Fair Value	0	0
U.S. Government sponsored enterprises
Estimated Fair Value	33,614	34,634
U.S. Government sponsored enterprises | Level 1
Estimated Fair Value	0	0
U.S. Government sponsored enterprises | Level 2
Estimated Fair Value	33,614	34,634
U.S. Government sponsored enterprises | Level 3
Estimated Fair Value	0	0
State and political subdivisions
Estimated Fair Value	96,933	107,591
State and political subdivisions | Level 1
Estimated Fair Value	0	0
State and political subdivisions | Level 2
Estimated Fair Value	96,933	107,591
State and political subdivisions | Level 3
Estimated Fair Value	0	0
Trust preferred securities
Estimated Fair Value	250	250
Trust preferred securities | Level 1
Estimated Fair Value	0	0
Trust preferred securities | Level 2
Estimated Fair Value	0	0
Trust preferred securities | Level 3
Estimated Fair Value	$ 250	$ 250