Investment Securities - Securities Pledged (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Realized gains and losses and the proceeds from sales of securities
Amortized cost	$ 685,728	$ 717,773
Asset Pledged as Collateral with Right [Member] | Deposits [Member]
Realized gains and losses and the proceeds from sales of securities
Amortized cost	555,800,000	272,800,000
Asset Pledged as Collateral with Right [Member] | Federal Reserve Bank discount window [Member]
Realized gains and losses and the proceeds from sales of securities
Amortized cost	74,000,000	$ 5,400,000
Asset Pledged as Collateral with Right [Member] | Federal Reserve Bank Bank Term Funding Program [Member]
Realized gains and losses and the proceeds from sales of securities
Amortized cost	$ 202,100,000