Securities - Contractual maturities of debt securities (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024
Amortized Cost
Due in one year or less	$ 11,654		$ 11,654
Due after one but within five years	44,532		44,532
Due after five but within ten years	131,477		131,477
Due after ten years	334,109		334,109
Total of securities having specified maturity period	521,772		521,772
Mortgage-backed securities and collateralized mortgage obligations	786,262		786,262
Amortized Cost	1,308,034		1,308,034		$ 1,361,797
Fair Value
Due in one year or less	11,621		11,621
Due after one but within five years	43,683		43,683
Due after five but within ten years	128,522		128,522
Due after ten years	300,408		300,408
Total of securities having specified maturities period	484,234		484,234
Mortgage-backed securities and collateralized mortgage obligations	701,873		701,873
TOTAL	1,186,107		1,186,107		$ 1,195,990
Gross gains	25	$ 132	25	$ 133
Gross loss	$ 1	$ 29	$ 4	$ 29