Short and Long-Term Funding, Composition (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Short-Term Debt [Abstract]
Federal Funds Purchased	$ 335,095	$ 370,325
Securities Sold under Agreements to Repurchase	64,570	100,044
Federal Funds Purchased and Securities Sold under Agreements to Repurchase, Total	399,665	470,369
Debt Instrument [Line Items]
Senior Notes	300,000	300,000
Subordinated Debt	300,000	550,000
Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net	(7,779)	(8,664)
Finance Lease, Liability	228	295
Long-term Debt	594,074	837,635
TotalShortTermLongTermExcludingFHLB	993,739	1,308,004
Federal Funds Purchased	335,095	370,325
Securities Sold under Agreements to Repurchase	64,570	100,044
Federal Funds Purchased and Securities Sold under Agreements to Repurchase	399,665	470,369
Advance from Federal Home Loan Bank	2,810,000	1,250,000
Long-Term Federal Home Loan Bank Advances	412,251	611,551
Federal Home Loan Bank, Advances, Branch of FHLB Bank, Amount of Advances	3,220,679	1,853,807
Debt, Long-Term and Short-Term, Combined Amount	4,214,418	3,161,811
Advance from Federal Home Loan Bank [Abstract]
Advance from Federal Home Loan Bank	2,810,000	1,250,000
Long-Term Federal Home Loan Bank Advances	412,251	611,551
Federal Home Loan Bank, Advances, Branch of FHLB Bank, Amount of Advances	3,220,679	1,853,807
Debt, Long-Term and Short-Term, Combined Amount	4,214,418	3,161,811
Fair Value Hedging [Member]
Debt Instrument [Line Items]
Subordinated Debt	1,626	(3,996)
Advance from Federal Home Loan Bank	(1,573)	(7,744)
Advance from Federal Home Loan Bank [Abstract]
Advance from Federal Home Loan Bank	$ (1,573)	$ (7,744)