Regulatory Capital Matters - Summary of Actual and Required Capital Amounts and Ratios (Details) $ in Thousands	Sep. 30, 2021 USD ($)	Dec. 31, 2020 USD ($)
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Total capital (to risk-weighted assets)	$ 172,873	$ 155,287
Tier 1 capital (to risk-weighted assets)	158,126	142,147
Common equity Tier 1 capital (to risk-weighted assets)	158,126	142,147
Tier 1 leverage (to average assets)	$ 158,126	$ 142,147
Total capital (to risk-weighted assets), ratio	0.1381	0.1481
Tier 1 capital (to risk-weighted assets), ratio	0.1263	0.1356
Common equity Tier 1 capital (to risk-weighted assets), ratio	0.1263	0.1356
Tier 1 leverage (to average assets), ratio	0.0975	0.1055
Bank
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Total capital (to risk-weighted assets)	$ 170,171	$ 152,232
Tier 1 capital (to risk-weighted assets)	155,424	139,092
Common equity Tier 1 capital (to risk-weighted assets)	155,424	139,092
Tier 1 leverage (to average assets)	$ 155,424	$ 139,092
Total capital (to risk-weighted assets), ratio	0.1360	0.1452
Tier 1 capital (to risk-weighted assets), ratio	0.1242	0.1327
Common equity Tier 1 capital (to risk-weighted assets), ratio	0.1242	0.1327
Tier 1 leverage (to average assets), ratio	0.0958	0.1032
Total capital (to risk-weighted assets), amount, Required for Capital Adequacy Purposes	$ 100,135	$ 83,859
Tier 1 capital (to risk-weighted assets), amount, Required for Capital Adequacy Purposes	75,101	62,894
Common equity Tier 1 capital (to risk-weighted assets), amount, Required for Capital Adequacy Purposes	56,326	47,171
Tier 1 leverage (to average assets), amount, Required for Capital Adequacy Purposes	$ 64,875	$ 53,915
Total capital (to risk-weighted assets), ratio, Required for Capital Adequacy Purposes	0.0800	0.0800
Tier 1 capital (to risk-weighted assets), ratio, Required for Capital Adequacy Purposes	0.0600	0.0600
Common equity Tier 1 capital (to risk-weighted assets), ratio, Required for Capital Adequacy Purposes	0.0450	0.0450
Tier 1 leverage (to average assets), ratio, Required for Capital Adequacy Purposes	0.0400	0.0400
Capital required to be well capitalized	$ 125,169	$ 104,824
Tier 1 capital (to risk-weighted assets), amount, Minimum To be Considered "Well Capitalized"	100,135	83,859
Common equity Tier 1 capital (to risk-weighted assets), amount, Minimum To be Considered "Well Capitalized"	81,360	68,136
Tier 1 leverage (to average assets), amount, Minimum To be Considered "Well Capitalized"	$ 81,094	$ 67,393
Total capital (to risk-weighted assets), ratio, Minimum To be Considered "Well Capitalized"	0.1000	0.001000
Tier 1 capital (to risk-weighted assets), ratio, Minimum To be Considered "Well Capitalized"	0.0800	0.000800
Common equity Tier 1 capital (to risk-weighted assets), ratio, Minimum To be Considered "Well Capitalized"	0.0650	0.0650
Tier 1 leverage (to average assets), ratio, Minimum To be Considered "Well Capitalized"	0.0500	0.000500