Investment Securities - Contractual maturities of investment securities (Details) $ in Thousands	Mar. 31, 2022 USD ($)
Held-to-maturity, Amortized Cost
Due after five years through ten years	$ 43,331
Due after ten years	60,846
Total Held-to-maturity Securities	104,177
Held-to-maturity, Fair Value
Due after five years through ten years	39,718
Due after ten years	55,333
Total Held-to-maturity Securities	95,051
Available-for-sale, Amortized Cost
Due in one year or less	1,045
Due after one year through five years	65,548
Due after five years through ten years	112,263
Due after ten years	133,522
Total Available-for-sale Securities	312,378
Available-for-sale, Fair Value
Due in one year or less	1,050
Due after one year through five years	63,018
Due after five years through ten years	107,900
Due after ten years	126,135
Total Available-for-sale Securities	$ 298,103