Investment Securities - Amortized cost and estimated fair value (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Carrying Value
Due within one year or less	$ 8,588
Due after one year through five years	47,995
Due after five years through ten years	60,289
Due after 10 years	12,731
Held-to-maturity securities carrying value	129,603
Amortized Cost	299,728	$ 321,902
Estimated Fair Value
Due within one year or less	8,474
Due after one year through five years	44,557
Due after five years through ten years	52,729
Due after 10 years	11,230
Total investment securities	116,990
Debt Securities, Held-to-maturity, Fair Value, Total	258,617	270,912
Amortized Cost
Due after one year through five years	524
Due after five years through ten years	59,477
Due after 10 years	613
Total investment securities available-for-sale	60,614
Total investment securities, Amortized Cost	584,754	849,567
Fair Value
Due after one year through five years	521
Due after five years through ten years	50,004
Due after 10 years	617
Total investment securities available-for-sale	51,142
Debt Securities, Available-for-sale, Total	486,736	717,324
Mortgage backed securities - Residential agency
Carrying Value
Mortgage-backed securities, Carrying value	170,125
Amortized Cost	170,125	184,115
Estimated Fair Value
Mortgage-backed securities, Fair value	141,627
Debt Securities, Held-to-maturity, Fair Value, Total	141,627	150,861
Amortized Cost
Mortgage-backed securities, Amortized Cost	524,140
Fair Value
Mortgage-backed securities, Fair value	435,594
Debt Securities, Available-for-sale, Total	$ 435,594	$ 587,679