Equity and Regulatory Matters - Schedule of Banks Actual and Required Capital Amounts and Ratios (Detail) $ in Thousands	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Text Block [Abstract]
Leverage tier 1 capital actual amount	$ 49,534	$ 46,316
Common Equity Tier 1 risk based capital actual amount	49,534	46,316
Tier 1 risk based capital actual amount	49,534	46,316
Total risk based capital actual amount	$ 52,237	$ 48,316
Leverage tier 1 capital actual ratio	0.098	0.107
Common Equity Tier 1 risk based capital actual ratio	0.151	0.135
Tier 1 risk based capital actual ratio	0.151	0.135
Total risk based capital actual ratio	0.160	0.141
Leverage tier 1 capital for capital adequacy purposes amount	$ 20,195	$ 17,392
Common Equity Tier 1 risk based capital for capital adequacy purposes amount	14,725	15,391
Tier 1 risk based capital for capital adequacy purposes amount	19,633	20,522
Total risk based capital for capital adequacy purposes amount	$ 26,177	$ 27,362
Leverage tier 1 capital for capital adequacy purposes ratio	4.00%	4.00%
Common Equity Tier 1 risk based capital for capital adequacy purposes ratio	0.045	0.045
Tier 1 risk based capital for capital adequacy purposes ratio	0.060	0.060
Total risk based capital for capital adequacy purposes ratio	0.080	0.080
Leverage tier 1 capital to be well capitalized under prompt corrective action provisions amount	$ 25,243	$ 21,740
Common Equity Tier 1 risk based capital to be well capitalized under prompt corrective action provisions amount	21,269	22,232
Tier 1 risk based capital to be well capitalized under prompt corrective action provisions amount	26,177	27,362
Total risk based capital to be well capitalized under prompt corrective action provisions amount	$ 32,722	$ 34,203
Leverage tier 1 capital to be well capitalized under prompt corrective action provisions ratio	5.00%	5.00%
Common Equity Tier 1 risk based capital to be well capitalized under prompt corrective action provisions ratio	0.065	0.065
Tier 1 risk based capital to be well capitalized under prompt corrective action provisions ratio	0.080	0.080
Total risk based capital to be well capitalized under prompt corrective action provisions ratio	0.100	0.100

Common Equity Tier One Capital Required To Be Well Capitalized To Risk Weighted Assets

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Common Equity Tier One Risk Based Capital Required For Capital Adequacy

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