Minimum Regulatory Capital Requirements - Summary of Actual and Minimum Capital Amounts and Ratios Exclusive of Capital Conservation Buffer (Detail) - Bank [Member] $ in Thousands	Mar. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Total capital (to risk weighted assets), actual amount	$ 89,621	$ 100,180
Tier 1 capital (to risk weighted assets), actual amount	82,471	93,288
Common equity Tier 1 capital (to risk weighted assets), actual amount	82,471	93,288
Tier 1 capital (to average assets), actual amount	$ 82,471	$ 93,288
Total capital (to risk weighted assets), actual ratio	0.154	0.174
Tier 1 capital (to risk weighted assets), actual ratio	0.142	0.162
Common equity Tier 1 capital (to risk weighted assets), actual ratio	14.20%	16.20%
Tier 1 capital (to average assets), actual ratio	0.105	0.123
Total capital (to risk weighted assets), for minimum capital adequacy purposes amount	$ 46,423	$ 45,956
Tier 1 capital (to risk weighted assets), for minimum capital adequacy purposes amount	34,817	34,467
Common equity Tier 1 capital (to risk weighted assets), for minimum capital adequacy amount	26,113	25,850
Common equity Tier 1 capital (to risk weighted assets), for minimum capital adequacy amount	$ 31,449	$ 30,355
Total capital (to risk weighted assets), for minimum capital adequacy purposes ratio	0.080	0.080
Tier 1 capital (to risk weighted assets), for minimum capital adequacy purposes ratio	0.060	0.060
Common equity Tier 1 capital (to risk weighted assets), for minimum capital adequacy purposes ratio	4.50%	4.50%
Tier 1 capital (to average assets), for minimum capital adequacy purposes ratio	0.040	0.040
Total capital (to risk weighted assets), minimum to be well capitalized under prompt corrective action provisions amount	$ 58,029	$ 57,445
Tier 1 capital (to risk weighted assets), minimum to be well capitalized under prompt corrective action provisions amount	46,423	45,956
Common equity Tier 1 capital (to risk weighted assets), minimum to be well capitalized under prompt corrective action provisions amount	37,719	37,339
Tier 1 capital (to average assets), minimum to be well capitalized under prompt corrective action provisions amount	$ 39,311	$ 37,943
Total capital (to risk weighted assets), minimum to be well capitalized under prompt corrective action provisions ratio	0.100	0.100
Tier 1 capital (to risk weighted assets), minimum to be well capitalized under prompt corrective action provisions ratio	0.080	0.080
Common equity Tier 1 capital (to risk weighted assets), minimum to be well capitalized under prompt corrective action provisions ratio	6.50%	6.50%
Tier 1 capital (to average assets), minimum to be well capitalized under prompt corrective action provisions ratio	0.050	0.050