Transfers of Financial Assets - Carrying Amounts of Assets Pledged as Collateral, Borrowings and Other Transactions (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2025	Dec. 31, 2024
Carrying amounts of the assets pledged as collateral
In-substance debt defeasance	$ 0	$ 0
Securities for reverse repurchase agreements	0	0
Asset Pledged as Collateral
Carrying amounts of the assets pledged as collateral
Assets pledged as collateral	10,632,724	10,294,047
Public deposits | Asset Pledged as Collateral with Right
Carrying amounts of the assets pledged as collateral
Assets pledged as collateral	1,875,118	1,729,131
Federal Home Loan Bank | Asset Pledged as Collateral
Carrying amounts of the assets pledged as collateral
Assets pledged as collateral	4,927,265	4,959,298
Federal Reserve Bank | Asset Pledged as Collateral
Carrying amounts of the assets pledged as collateral
Assets pledged as collateral	3,830,010	3,605,233
Interest rate swaps | Asset Pledged as Collateral without Right
Carrying amounts of the assets pledged as collateral
Assets pledged as collateral	$ 331	$ 385