Investment Securities - Pledged Securities (Details) - USD ($) $ in Thousands		Dec. 31, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Held-to-maturity	[1]	$ 683,657	$ 560,212
Asset Pledged as Collateral | Securing public and trust department deposits, and Repurchase Agreements:
Debt Securities, Available-for-sale [Line Items]
Available-for-sale		713,033	779,244
Held-to-maturity		559,142	312,921
Asset Pledged as Collateral | Securing additional borrowing capacity at the FHLB and the FRB:
Debt Securities, Available-for-sale [Line Items]
Available-for-sale		85,899	3,972
Held-to-maturity		$ 39,607	$ 128,870

[1] Available-for-sale investment securities and held-to-maturity investment securities are presented net of allowance for credit losses of $0 and $238, respectively, at December 31, 2023 and $0 and $241, respectively, at December 31, 2022.