Loans Receivable and Allowance for Loan Losses - Summary of credit risk ratings by loan segment (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Financing Receivable, Recorded Investment
Total loans	$ 2,286,793	$ 1,894,881
Commercial Real Estate
Financing Receivable, Recorded Investment
Total loans	1,647,928	1,356,709
Construction
Financing Receivable, Recorded Investment
Total loans	117,355	98,341
Commercial business
Financing Receivable, Recorded Investment
Total loans	443,288	350,975
Residential Real Estate
Financing Receivable, Recorded Investment
Total loans	61,664	79,987
Consumer
Financing Receivable, Recorded Investment
Total loans	16,558	8,869
Commercial Credit Quality Indicators
Financing Receivable, Recorded Investment
Total loans	2,208,571	1,806,025
Commercial Credit Quality Indicators | Pass
Financing Receivable, Recorded Investment
Total loans	2,167,718	1,742,489
Commercial Credit Quality Indicators | Special Mention
Financing Receivable, Recorded Investment
Total loans	1,456	20,505
Commercial Credit Quality Indicators | Substandard
Financing Receivable, Recorded Investment
Total loans	39,099	41,099
Commercial Credit Quality Indicators | Doubtful
Financing Receivable, Recorded Investment
Total loans	298	1,932
Commercial Credit Quality Indicators | Loss
Financing Receivable, Recorded Investment
Total loans	0	0
Commercial Credit Quality Indicators | Commercial Real Estate
Financing Receivable, Recorded Investment
Total loans	1,647,928	1,356,709
Commercial Credit Quality Indicators | Commercial Real Estate | Pass
Financing Receivable, Recorded Investment
Total loans	1,621,467	1,307,992
Commercial Credit Quality Indicators | Commercial Real Estate | Special Mention
Financing Receivable, Recorded Investment
Total loans	1,016	19,051
Commercial Credit Quality Indicators | Commercial Real Estate | Substandard
Financing Receivable, Recorded Investment
Total loans	25,370	29,255
Commercial Credit Quality Indicators | Commercial Real Estate | Doubtful
Financing Receivable, Recorded Investment
Total loans	75	411
Commercial Credit Quality Indicators | Commercial Real Estate | Loss
Financing Receivable, Recorded Investment
Total loans	0	0
Commercial Credit Quality Indicators | Construction
Financing Receivable, Recorded Investment
Total loans	117,355	98,341
Commercial Credit Quality Indicators | Construction | Pass
Financing Receivable, Recorded Investment
Total loans	107,973	89,344
Commercial Credit Quality Indicators | Construction | Special Mention
Financing Receivable, Recorded Investment
Total loans	0	0
Commercial Credit Quality Indicators | Construction | Substandard
Financing Receivable, Recorded Investment
Total loans	9,382	8,997
Commercial Credit Quality Indicators | Construction | Doubtful
Financing Receivable, Recorded Investment
Total loans	0	0
Commercial Credit Quality Indicators | Construction | Loss
Financing Receivable, Recorded Investment
Total loans	0	0
Commercial Credit Quality Indicators | Commercial business
Financing Receivable, Recorded Investment
Total loans	443,288	350,975
Commercial Credit Quality Indicators | Commercial business | Pass
Financing Receivable, Recorded Investment
Total loans	438,278	345,153
Commercial Credit Quality Indicators | Commercial business | Special Mention
Financing Receivable, Recorded Investment
Total loans	440	1,454
Commercial Credit Quality Indicators | Commercial business | Substandard
Financing Receivable, Recorded Investment
Total loans	4,347	2,847
Commercial Credit Quality Indicators | Commercial business | Doubtful
Financing Receivable, Recorded Investment
Total loans	223	1,521
Commercial Credit Quality Indicators | Commercial business | Loss
Financing Receivable, Recorded Investment
Total loans	0	0
Residential and Consumer Credit Quality Indicators
Financing Receivable, Recorded Investment
Total loans	78,222	88,856
Residential and Consumer Credit Quality Indicators | Pass
Financing Receivable, Recorded Investment
Total loans	74,233	84,561
Residential and Consumer Credit Quality Indicators | Special Mention
Financing Receivable, Recorded Investment
Total loans	145	145
Residential and Consumer Credit Quality Indicators | Substandard
Financing Receivable, Recorded Investment
Total loans	3,844	3,975
Residential and Consumer Credit Quality Indicators | Doubtful
Financing Receivable, Recorded Investment
Total loans	0	175
Residential and Consumer Credit Quality Indicators | Loss
Financing Receivable, Recorded Investment
Total loans	0	0
Residential and Consumer Credit Quality Indicators | Residential Real Estate
Financing Receivable, Recorded Investment
Total loans	61,664	79,987
Residential and Consumer Credit Quality Indicators | Residential Real Estate | Pass
Financing Receivable, Recorded Investment
Total loans	57,675	75,692
Residential and Consumer Credit Quality Indicators | Residential Real Estate | Special Mention
Financing Receivable, Recorded Investment
Total loans	145	145
Residential and Consumer Credit Quality Indicators | Residential Real Estate | Substandard
Financing Receivable, Recorded Investment
Total loans	3,844	3,975
Residential and Consumer Credit Quality Indicators | Residential Real Estate | Doubtful
Financing Receivable, Recorded Investment
Total loans	0	175
Residential and Consumer Credit Quality Indicators | Residential Real Estate | Loss
Financing Receivable, Recorded Investment
Total loans	0	0
Residential and Consumer Credit Quality Indicators | Consumer
Financing Receivable, Recorded Investment
Total loans	16,558	8,869
Residential and Consumer Credit Quality Indicators | Consumer | Pass
Financing Receivable, Recorded Investment
Total loans	16,558	8,869
Residential and Consumer Credit Quality Indicators | Consumer | Special Mention
Financing Receivable, Recorded Investment
Total loans	0	0
Residential and Consumer Credit Quality Indicators | Consumer | Substandard
Financing Receivable, Recorded Investment
Total loans	0	0
Residential and Consumer Credit Quality Indicators | Consumer | Doubtful
Financing Receivable, Recorded Investment
Total loans	0	0
Residential and Consumer Credit Quality Indicators | Consumer | Loss
Financing Receivable, Recorded Investment
Total loans	$ 0	$ 0