Regulatory Capital - Capital Amounts and Ratios (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Total Risk-Based Capital
Total Risk-Based Capital, Actual amount	$ 269,613	$ 263,909
Total Risk-Based Capital, For Capital Adequacy Purposes, amount	166,163	145,111
Total Risk-Based Capital, For Capital Adequacy Purposes Plus Capital Conversion Buffer, amount	$ 218,089	$ 179,121
Total Risk-Based Capital, Actual ratio	12.98%	14.55%
Total Risk-Based Capital, For Capital Adequacy Purposes, Ratio	8.00%	8.00%
Total Risk-Based Capital, For Capital Adequacy Purposes Plus Capital Conservation Buffer, Ratio	10.50%	9.875%
Tier 1 Risk-Based Capital
Tier One Risk Based Capital	$ 236,533	$ 218,888
Tier 1 Risk-Based Capital, For Capital Adequacy Purposes, amount	124,623	108,833
Tier 1 Risk-Based Capital, For Capital Adequacy Purposes Plus Capital Conservation Buffer, amount	$ 176,549	$ 142,844
Tier 1 Risk-Based Capital, Actual ratio	11.39%	12.07%
Tier 1 Risk-Based Capital, For Capital Adequacy Purposes, Ratio	6.00%	6.00%
Tier 1 Risk-Based Capital, For Capital Adequacy Purposes Plus Capital Conservation Buffer, Ratio	8.50%	7.875%
Common Equity Tier 1 Capital
Common Equity Tier 1 Capital, Actual amount	$ 236,533	$ 218,888
Common Equity Tier 1 Capital, For Capital Adequacy Purposes, amount	93,467	81,625
Common Equity Tier 1 Capital, For Capital Adequacy Purposes Plus Capital Conservation Buffer, amount	$ 145,393	$ 115,635
Common Equity Tier 1 Capital, Actual ratio	11.39%	12.07%
Common Equity Tier 1 Capital, For Capital Adequacy Purposes, Ratio	4.50%	4.50%
Common Equity Tier 1 Capital, For Capital Adequacy Purposes Plus Capital Conservation Buffer, Ratio	7.00%	6.375%
Leverage Ratio
Tier 1 Leverage Ratio, Actual amount	$ 236,533	$ 218,888
Tier 1 Leverage Ratio, For Capital Adequacy Purposes, amount	88,498	77,971
Tier 1 Leverage Ratio, For Capital Adequacy Purposes Plus Capital Conservation Buffer, amount	$ 88,498	$ 77,971
Tier 1 Leverage Ratio, Actual ratio	10.69%	11.23%
Tier 1 Leverage Ratio, For Capital Adequacy Purposes, Ratio	4.00%	4.00%
Tier 1 Leverage Ratio, For Capital Adequacy Purposes Plus Capital Conservation Buffer, Ratio	4.00%	4.00%
Capital conservation buffer (as a percent)	2.50%	1.875%
Bank
Total Risk-Based Capital
Total Risk-Based Capital, Actual amount	$ 252,501	$ 230,865
Total Risk-Based Capital, For Capital Adequacy Purposes, amount	166,137	144,776
Total Risk-Based Capital, For Capital Adequacy Purposes Plus Capital Conversion Buffer, amount	218,055	178,707
Total Risk-Based Capital, To be Well Capitalized Under Prompt Corrective Action Regulations, amount	$ 207,671	$ 180,970
Total Risk-Based Capital, Actual ratio	12.16%	12.76%
Total Risk-Based Capital, For Capital Adequacy Purposes, Ratio	8.00%	8.00%
Total Risk-Based Capital, For Capital Adequacy Purposes Plus Capital Conservation Buffer, Ratio	10.50%	9.875%
Total Risk-Based Capital, To be Well Capitalized Under Prompt Corrective Action Regulations, Ratio	10.00%	10.00%
Tier 1 Risk-Based Capital
Tier One Risk Based Capital	$ 243,461	$ 210,474
Tier 1 Risk-Based Capital, For Capital Adequacy Purposes, amount	124,603	108,582
Tier 1 Risk-Based Capital, For Capital Adequacy Purposes Plus Capital Conservation Buffer, amount	176,521	142,514
Tier 1 Risk-Based Capital, To be Well Capitalized Under Prompt Corrective Action Regulations, amount	$ 166,137	$ 144,776
Tier 1 Risk-Based Capital, Actual ratio	11.72%	11.63%
Tier 1 Risk-Based Capital, For Capital Adequacy Purposes, Ratio	6.00%	6.00%
Tier 1 Risk-Based Capital, For Capital Adequacy Purposes Plus Capital Conservation Buffer, Ratio	8.50%	7.875%
Tier 1 Risk-Based Capital, To be Well Capitalized Under Prompt Corrective Action Regulations, Ratio	8.00%	8.00%
Common Equity Tier 1 Capital
Common Equity Tier 1 Capital, Actual amount	$ 243,461	$ 210,474
Common Equity Tier 1 Capital, For Capital Adequacy Purposes, amount	93,452	81,436
Common Equity Tier 1 Capital, For Capital Adequacy Purposes Plus Capital Conservation Buffer, amount	145,370	115,368
Common Equity Tier 1 Capital, To be Well Capitalized Under Prompt Corrective Action Regulations, amount	$ 134,986	$ 117,630
Common Equity Tier 1 Capital, Actual ratio	11.72%	11.63%
Common Equity Tier 1 Capital, For Capital Adequacy Purposes, Ratio	4.50%	4.50%
Common Equity Tier 1 Capital, For Capital Adequacy Purposes Plus Capital Conservation Buffer, Ratio	7.00%	6.375%
Common Equity Tier 1 Capital, To be Well Capitalized Under Prompt Corrective Action Regulations, Ratio	6.50%	6.50%
Leverage Ratio
Tier 1 Leverage Ratio, Actual amount	$ 243,461	$ 210,474
Tier 1 Leverage Ratio, For Capital Adequacy Purposes, amount	88,455	77,795
Tier 1 Leverage Ratio, For Capital Adequacy Purposes Plus Capital Conservation Buffer, amount	88,455	77,795
Tier 1 Leverage Ratio, To be Well Capitalized Under Prompt Corrective Action Regulations, amount	$ 110,569	$ 97,244
Tier 1 Leverage Ratio, Actual ratio	11.01%	10.82%
Tier 1 Leverage Ratio, For Capital Adequacy Purposes, Ratio	4.00%	4.00%
Tier 1 Leverage Ratio, For Capital Adequacy Purposes Plus Capital Conservation Buffer, Ratio	4.00%	4.00%
Tier 1 Leverage Ratio, To be Well Capitalized Under Prompt Corrective Action Regulations, Ratio	5.00%	5.00%