Investment Securities - Amortized cost and estimated fair value (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Carrying Value
Due within one year or less	$ 6,554
Due after one year through five years	40,317
Due after five years through ten years	69,992
Due after 10 years	205,039
Total investment securities	321,902
Estimated Fair Value
Due within one year or less	6,522
Due after one year through five years	37,146
Due after five years through ten years	59,138
Due after 10 years	168,106
Total investment securities	270,912
Amortized Cost
Due within one year or less	4
Due after one year through five years	21,256
Due after five years through ten years	87,961
Due after 10 years	740,346
Total investment securities available-for-sale	849,567
Fair Value
Due within one year or less	4
Due after one year through five years	19,863
Due after five years through ten years	79,697
Due after 10 years	617,760
Total investment securities available-for-sale	$ 717,324