Loans Receivable - Summary of Performance and Credit Quality of Loan Portfolio (Detail) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Financing Receivable Performance and Credit Quality Indicators [Line Items]
Current	$ 1,569,711	$ 1,542,934
Total loans receivable	1,573,556	1,550,133
Loans receivable more than 90 days and accruing	0	0
Commercial real estate [Member]
Financing Receivable Performance and Credit Quality Indicators [Line Items]
Current	1,160,199	1,138,220
Total loans receivable	1,162,741	1,142,864
Loans receivable more than 90 days and accruing	0	0
Commercial and industrial [Member]
Financing Receivable Performance and Credit Quality Indicators [Line Items]
Current	44,788	48,542
Total loans receivable	45,930	50,961
Loans receivable more than 90 days and accruing	0	0
Construction [Member]
Financing Receivable Performance and Credit Quality Indicators [Line Items]
Current	321,009	310,187
Total loans receivable	321,009	310,187
Loans receivable more than 90 days and accruing	0	0
Residential first-lien mortgage [Member]
Financing Receivable Performance and Credit Quality Indicators [Line Items]
Current	36,404	37,933
Total loans receivable	36,565	38,040
Loans receivable more than 90 days and accruing	0	0
Home equity/consumer [Member]
Financing Receivable Performance and Credit Quality Indicators [Line Items]
Current	7,311	8,052
Total loans receivable	7,311	8,081
Loans receivable more than 90 days and accruing	0	0
30 to 59 Days Past Due [Member]
Financing Receivable Performance and Credit Quality Indicators [Line Items]
Total	615	491
30 to 59 Days Past Due [Member] | Commercial real estate [Member]
Financing Receivable Performance and Credit Quality Indicators [Line Items]
Total	356	159
30 to 59 Days Past Due [Member] | Commercial and industrial [Member]
Financing Receivable Performance and Credit Quality Indicators [Line Items]
Total	232	303
30 to 59 Days Past Due [Member] | Construction [Member]
Financing Receivable Performance and Credit Quality Indicators [Line Items]
Total	0	0
30 to 59 Days Past Due [Member] | Residential first-lien mortgage [Member]
Financing Receivable Performance and Credit Quality Indicators [Line Items]
Total	27	0
30 to 59 Days Past Due [Member] | Home equity/consumer [Member]
Financing Receivable Performance and Credit Quality Indicators [Line Items]
Total	0	29
60 to 89 Days Past Due [Member]
Financing Receivable Performance and Credit Quality Indicators [Line Items]
Total	1,115	0
60 to 89 Days Past Due [Member] | Commercial real estate [Member]
Financing Receivable Performance and Credit Quality Indicators [Line Items]
Total	841	0
60 to 89 Days Past Due [Member] | Commercial and industrial [Member]
Financing Receivable Performance and Credit Quality Indicators [Line Items]
Total	274	0
60 to 89 Days Past Due [Member] | Construction [Member]
Financing Receivable Performance and Credit Quality Indicators [Line Items]
Total	0	0
60 to 89 Days Past Due [Member] | Residential first-lien mortgage [Member]
Financing Receivable Performance and Credit Quality Indicators [Line Items]
Total	0	0
60 to 89 Days Past Due [Member] | Home equity/consumer [Member]
Financing Receivable Performance and Credit Quality Indicators [Line Items]
Total	0	0
Greater than 90 Days [Member]
Financing Receivable Performance and Credit Quality Indicators [Line Items]
Total	2,115	6,708
Greater than 90 Days [Member] | Commercial real estate [Member]
Financing Receivable Performance and Credit Quality Indicators [Line Items]
Total	1,345	4,485
Greater than 90 Days [Member] | Commercial and industrial [Member]
Financing Receivable Performance and Credit Quality Indicators [Line Items]
Total	636	2,116
Greater than 90 Days [Member] | Construction [Member]
Financing Receivable Performance and Credit Quality Indicators [Line Items]
Total	0	0
Greater than 90 Days [Member] | Residential first-lien mortgage [Member]
Financing Receivable Performance and Credit Quality Indicators [Line Items]
Total	134	107
Greater than 90 Days [Member] | Home equity/consumer [Member]
Financing Receivable Performance and Credit Quality Indicators [Line Items]
Total	0	0
Past Due [Member]
Financing Receivable Performance and Credit Quality Indicators [Line Items]
Total	3,845	7,199
Past Due [Member] | Commercial real estate [Member]
Financing Receivable Performance and Credit Quality Indicators [Line Items]
Total	2,542	4,644
Past Due [Member] | Commercial and industrial [Member]
Financing Receivable Performance and Credit Quality Indicators [Line Items]
Total	1,142	2,419
Past Due [Member] | Construction [Member]
Financing Receivable Performance and Credit Quality Indicators [Line Items]
Total	0	0
Past Due [Member] | Residential first-lien mortgage [Member]
Financing Receivable Performance and Credit Quality Indicators [Line Items]
Total	161	107
Past Due [Member] | Home equity/consumer [Member]
Financing Receivable Performance and Credit Quality Indicators [Line Items]
Total	$ 0	$ 29