Investment Securities - Investments Classified by Contractual Maturity Date (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Amortized Cost
Due in 1 year or less	$ 6,995
Due after 1 year but within 5 years	37,872
Due after 5 years but within 10 years	29,472
Due after 10 years	2,337
Available-for-sale securities, amortized cost basis, Total	76,676
Amortized Cost	249,736	$ 262,342
Fair Value
Due in 1 year or less	6,878
Due after 1 year but within 5 years	36,109
Due after 5 years but within 10 years	24,686
Due after 10 years	1,747
Available-for-sale securities, fair value, Total	69,420
Available-for-sale securities, fair value	218,064	237,878
Amortized Cost
Due in 1 year or less	8,076
Due after 1 year but within 5 years	94,702
Due after 5 years but within 10 years	209,213
Due after 10 years	44,196
Held-to-maturity securities, amortized cost	356,187
Amortized Cost	401,561	399,494
Fair Value
Due in 1 year or less	7,960
Due after 1 year but within 5 years	86,955
Due after 5 years but within 10 years	172,101
Due after 10 years	36,230
Held-to-maturity securities, fair value	303,246
Held-to-maturity, Fair Value	341,006	$ 348,505
Mortgage-backed securities
Amortized Cost
Mortgage-backed securities	173,060
Fair Value
Mortgage-backed securities	148,644
Amortized Cost
Mortgage-backed securities	45,374
Fair Value
Mortgage-backed securities	$ 37,760