Investment Securities - Amortized cost and estimated fair value (Details) $ in Thousands	Jun. 30, 2022 USD ($)
Carrying Value
Due within one year or less	$ 6,831
Due after one year through five years	36,025
Due after five years through ten years	72,720
Due after 10 years	216,165
Total investment securities	331,741
Estimated Fair Value
Due within one year or less	6,794
Due after one year through five years	33,922
Due after five years through ten years	65,003
Due after 10 years	188,230
Total investment securities	293,949
Amortized Cost
Due within one year or less	20
Due after one year through five years	21,599
Due after five years through ten years	94,957
Due after 10 years	776,949
Total investment securities available-for-sale	893,525
Fair Value
Due within one year or less	21
Due after one year through five years	21,017
Due after five years through ten years	91,522
Due after 10 years	686,237
Total investment securities available-for-sale	$ 798,797