Loans and Allowance for Loan Losses - Credit Quality Indicators (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Credit Quality Indicators
Minimum outstanding balance of loans to be reviewed on a monthly basis	$ 25
Total loans	360,470	$ 359,391
Pass
Credit Quality Indicators
Total loans	353,540	354,709
Special Mention
Credit Quality Indicators
Total loans	719	741
Substandard
Credit Quality Indicators
Total loans	6,211	3,941
Commercial | Commercial
Credit Quality Indicators
Total loans	60,075	60,388
Commercial | Commercial | Pass
Credit Quality Indicators
Total loans	58,738	59,990
Commercial | Commercial | Substandard
Credit Quality Indicators
Total loans	1,337	398
Real estate | Residential Real Estate
Credit Quality Indicators
Total loans	78,808	78,422
Real estate | Residential Real Estate | Pass
Credit Quality Indicators
Total loans	78,338	77,982
Real estate | Residential Real Estate | Substandard
Credit Quality Indicators
Total loans	470	440
Construction | Commercial Real Estate
Credit Quality Indicators
Total loans	50,775	38,168
Construction | Commercial Real Estate | Pass
Credit Quality Indicators
Total loans	50,775	38,168
Auto | Consumer
Credit Quality Indicators
Total loans	1,121	1,195
Auto | Consumer | Pass
Credit Quality Indicators
Total loans	1,121	1,195
Other | Commercial Real Estate
Credit Quality Indicators
Total loans	166,819	178,343
Other | Commercial Real Estate | Pass
Credit Quality Indicators
Total loans	161,707	174,507
Other | Commercial Real Estate | Special Mention
Credit Quality Indicators
Total loans	719	741
Other | Commercial Real Estate | Substandard
Credit Quality Indicators
Total loans	4,393	3,095
Other | Consumer
Credit Quality Indicators
Total loans	2,872	2,875
Other | Consumer | Pass
Credit Quality Indicators
Total loans	2,861	2,867
Other | Consumer | Substandard
Credit Quality Indicators
Total loans	$ 11	$ 8