Investment Securities - Amortized cost and estimated fair value (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Carrying Value
Due within one year or less	$ 8,161
Due after one year through five years	47,376
Due after five years through ten years	57,248
Due after 10 years	12,186
Held-to-maturity securities carrying value	124,971
Amortized Cost	292,139	$ 299,728
Estimated Fair Value
Due within one year or less	7,974
Due after one year through five years	43,614
Due after five years through ten years	49,662
Due after 10 years	10,736
Total investment securities	111,986
Debt Securities, Held-to-maturity, Fair Value, Total	249,807	258,617
Amortized Cost
Due after one year through five years	473
Due after five years through ten years	59,467
Due after 10 years	384
Total investment securities available-for-sale	60,324
Total investment securities, Amortized Cost	573,733	584,754
Fair Value
Due after one year through five years	470
Due after five years through ten years	50,524
Due after 10 years	385
Total investment securities available-for-sale	51,379
Debt Securities, Available-for-sale, Total	472,272	486,736
Mortgage backed securities - Residential agency
Carrying Value
Mortgage-backed securities, Carrying value	167,168
Amortized Cost	167,168	170,125
Estimated Fair Value
Mortgage-backed securities, Fair value	137,821
Debt Securities, Held-to-maturity, Fair Value, Total	137,821	141,627
Amortized Cost
Mortgage-backed securities, Amortized Cost	513,409
Fair Value
Mortgage-backed securities, Fair value	420,893
Debt Securities, Available-for-sale, Total	$ 420,893	$ 435,594