Short-Term Borrowings (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024
Short-Term Borrowings
Short-term borrowings	$ 250,000		$ 250,000
Federal Reserve Bank
Short-Term Borrowings
Borrowing capacity	3,400,000		3,000,000
Short-term FHLB fixed-rate advances
Short-Term Borrowings
Short-term borrowings	$ 250,000		$ 250,000
Weighted-average interest rate (as a percent)	4.16%	4.71%	4.16%
Borrowing capacity	$ 2,700,000		$ 2,800,000
Highest month-end balance	250,000	$ 500,000
Average outstanding balance	$ 250,000	$ 500,000
Weighted-average interest rate paid (as a percent)	4.22%	4.79%