Investment Securities - Carrying value of other investment securities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Other investment securities
Carrying Value	$ 187,152	$ 179,717
Federal Home Loan Bank stock
Other investment securities
Carrying Value	18,085	15,085
Federal Reserve Bank Stock
Other investment securities
Carrying Value	150,261	150,261
Investment in unconsolidated subsidiaries
Other investment securities
Carrying Value	3,563	3,563
Other nonmarketable investment securities
Other investment securities
Carrying Value	$ 15,243	$ 10,808