Investment Securities, Contractual Maturity (Details) $ in Thousands	Sep. 30, 2023 USD ($)
Amortized Cost [Abstract]
One year or less	$ 387
After one year through five years	17,771
After five years through ten years	6,561
After ten years	110,406
Total	135,125
Fair Value [Abstract]
One year or less	386
After one year through five years	17,321
After five years through ten years	6,121
After ten years	82,665
Total	106,493
Amortized Cost [Abstract]
One year or less	450
After one year through five years	16,910
After five years through ten years	24,031
After ten years	784,624
Fair value, excluding securities without single maturity date	826,015
Fair Value [Abstract]
One year or less	450
After one year through five years	16,335
After five years through ten years	21,844
After ten years	597,994
Fair value, excluding investment securities without single maturity date	$ 636,623