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Commitments and Contingencies - Schedule of contract amounts represents off-balance sheet (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Commitment and Contingencies
Amount of financial instruments represents off-balance sheet credit risk	$ 1,090,341	$ 952,339
Commitments to originate loans
Commitment and Contingencies
Amount of financial instruments represents off-balance sheet credit risk	22,141	34,050
Unadvanced funds on lines of credit
Commitment and Contingencies
Amount of financial instruments represents off-balance sheet credit risk	636,648	495,796
Unadvanced funds on construction loans
Commitment and Contingencies
Amount of financial instruments represents off-balance sheet credit risk	425,944	416,450
Letter of credit
Commitment and Contingencies
Amount of financial instruments represents off-balance sheet credit risk	$ 5,608	$ 6,043

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