Investment Securities - Amortized cost and estimated fair value (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Carrying Value
Due within one year or less	$ 6,098
Due after one year through five years	44,352
Due after five years through ten years	67,751
Due after 10 years	12,815
Held-to-maturity securities carrying value	131,016
Amortized Cost	308,634	$ 321,902
Estimated Fair Value
Due within one year or less	5,946
Due after one year through five years	40,512
Due after five years through ten years	58,000
Due after 10 years	11,111
Total investment securities	115,569
Debt Securities, Held-to-maturity, Fair Value, Total	260,710	270,912
Amortized Cost
Due after one year through five years	17,461
Due after five years through ten years	78,734
Due after 10 years	44,624
Total investment securities available-for-sale	140,819
Total investment securities, Amortized Cost	814,405
Fair Value
Due after one year through five years	16,096
Due after five years through ten years	63,524
Due after 10 years	39,378
Total investment securities available-for-sale	118,998
Debt Securities, Available-for-sale, Total	677,454	717,324
Mortgage backed securities - Residential agency
Carrying Value
Mortgage-backed securities, Carrying value	177,618
Amortized Cost	177,618	184,115
Estimated Fair Value
Mortgage-backed securities, Fair value	145,141
Debt Securities, Held-to-maturity, Fair Value, Total	145,141	150,861
Amortized Cost
Mortgage-backed securities, Amortized Cost	673,586
Fair Value
Mortgage-backed securities, Fair value	558,456
Debt Securities, Available-for-sale, Total	$ 558,456	$ 587,679