Regulatory Requirements and Restrictions - Capital Amounts and Ratios (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Regulatory requirements
Risk-weighted assets	$ 1,200,000	$ 1,180,000
Total Capital (to Risk-Weighted Assets)
Actual (in Dollars)	$ 183,781	$ 170,376
Actual	15.30%	14.40%
Minimum capital requirements (in Dollars)	$ 96,274	$ 94,383
Minimum capital requirements	8.00%	8.00%
Tier 1 Capital (to Risk-Weighted Assets)
Actual (in Dollars)	$ 168,504	$ 155,370
Actual	14.00%	13.20%
Minimum capital requirements (in Dollars)	$ 72,205	$ 70,787
Minimum capital requirements	6.00%	6.00%
Common Equity Tier 1 Capital (to Risk-Weighted Assets)
Actual (in Dollars)	$ 143,590	$ 130,445
Actual	11.90%	11.10%
Minimum capital requirements (in Dollars)	$ 54,154	$ 53,091
Minimum capital requirements	4.50%	4.50%
Tier 1 Capital (to Average Tangible Assets)
Actual (in Dollars)	$ 168,504	$ 155,370
Actual	11.30%	10.50%
Minimum capital requirements (in Dollars)	$ 59,759	$ 59,083
Minimum capital requirements	4.00%	4.00%
The Bank
Total Capital (to Risk-Weighted Assets)
Actual (in Dollars)	$ 181,685	$ 167,657
Actual	15.10%	14.20%
Minimum capital requirements (in Dollars)	$ 96,088	$ 94,163
Minimum capital requirements	8.00%	8.00%
Minimum to be well capitalized under prompt corrective action provisions (in Dollars)	$ 120,110	$ 117,704
Minimum to be well capitalized under prompt corrective action provisions	10.00%	10.00%
Tier 1 Capital (to Risk-Weighted Assets)
Actual (in Dollars)	$ 166,437	$ 152,684
Actual	13.90%	13.00%
Minimum capital requirements (in Dollars)	$ 72,066	$ 70,622
Minimum capital requirements	6.00%	6.00%
Minimum to be well capitalized under prompt corrective action provisions (in Dollars)	$ 96,088	$ 94,163
Minimum to be well capitalized under prompt corrective action provisions	8.00%	8.00%
Common Equity Tier 1 Capital (to Risk-Weighted Assets)
Actual (in Dollars)	$ 166,437	$ 152,684
Actual	13.90%	13.00%
Minimum capital requirements (in Dollars)	$ 54,050	$ 52,967
Minimum capital requirements	4.50%	4.50%
Minimum to be well capitalized under prompt corrective action provisions (in Dollars)	$ 78,072	$ 76,507
Minimum to be well capitalized under prompt corrective action provisions	6.50%	6.50%
Tier 1 Capital (to Average Tangible Assets)
Actual (in Dollars)	$ 166,437	$ 152,684
Actual	11.20%	10.40%
Minimum capital requirements (in Dollars)	$ 59,666	$ 58,934
Minimum capital requirements	4.00%	4.00%
Minimum to be well capitalized under prompt corrective action provisions (in Dollars)	$ 74,582	$ 73,667
Minimum to be well capitalized under prompt corrective action provisions	5.00%	5.00%