Investment Securities - Amortized Cost and Fair Value of Investment Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Sep. 01, 2022
Amortized Cost
Due in one year or less	$ 1,014
Due after one year through five years	15,542
Due after five years through ten years	95,886
Due after ten years	99,796
Total amortized cost	212,238
Mortgage-backed securities	251,658
Amortized Cost	463,896	$ 490,206
Fair Value
Due in one year or less	1,002
Due after one year through five years	14,127
Due after five years through ten years	79,640
Due after ten years	85,653
Total fair value	180,422
Mortgage-backed securities	219,125
Fair value	399,547	432,553
Amortized Cost
Due in one year or less	0
Due after one year through five years	91,725
Due after five years through ten years	75,296
Due after ten years	78,719
Total amortized cost	245,740
Mortgage-backed securities	205,316
Amortized Cost	451,056	465,858
Fair Value
Due in one year or less	0
Due after one year through five years	86,380
Due after five years through ten years	64,377
Due after ten years	64,539
Total fair value	215,296
Mortgage-backed securities	169,769
Fair value	$ 385,065	$ 411,264	$ 477,000