Regulatory Capital Requirements - Schedule of Bank Actual and Required Capital Amounts and Ratios (Detail) $ in Thousands	Sep. 30, 2025 USD ($)	Dec. 31, 2024 USD ($)
Total capital
Actual	$ 313,713	$ 282,736
For capital adequacy purposes	203,872	195,914
To be well capitalized	254,839	244,892
Tier 1 capital
Actual	290,271	263,058
For capital adequacy purposes	152,904	146,935
To be well capitalized	203,872	195,914
Common equity
Actual	290,271	263,058
For capital adequacy purposes	114,678	110,201
To be well capitalized	165,646	159,180
Tier 1 capital
Actual	290,271	263,058
For capital adequacy purposes	116,644	110,867
To be well capitalized	$ 145,805	$ 138,584
Ratios
Actual	0.1231	0.1155
For capital adequacy purposes	0.08	0.08
To be well capitalized	0.10	0.10
Actual	0.1139	0.1074
For capital adequacy purposes	0.06	0.06
To be well capitalized	0.08	0.08
Actual	0.0995	0.0949
For capital adequacy purposes	0.045	0.045
To be well capitalized	0.065	0.065
Banking Regulation, Leverage Ratio [Abstract]
Actual	0.1139	0.1074
For capital adequacy purposes	0.04	0.04
To be well capitalized	0.05	0.05