Transfers of Financial Assets - Carrying Amounts of Assets Pledged as Collateral, Borrowings and Other Transactions (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2025	Dec. 31, 2024
Carrying amounts of the assets pledged as collateral
Securities for reverse repurchase agreements	$ 0	$ 0
In-substance debt defeasance	0	0
Asset Pledged as Collateral
Carrying amounts of the assets pledged as collateral
Assets pledged as collateral	10,636,559	10,294,047
Public deposits | Asset Pledged as Collateral with Right
Carrying amounts of the assets pledged as collateral
Assets pledged as collateral	1,745,433	1,729,131
Federal Home Loan Bank | Asset Pledged as Collateral
Carrying amounts of the assets pledged as collateral
Assets pledged as collateral	4,858,872	4,959,298
Federal Reserve Bank | Asset Pledged as Collateral
Carrying amounts of the assets pledged as collateral
Assets pledged as collateral	$ 4,032,254	3,605,233
Interest rate derivatives | Asset Pledged as Collateral without Right
Carrying amounts of the assets pledged as collateral
Assets pledged as collateral		$ 385