Short and Long-Term Funding, Composition (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Short-Term Debt [Abstract]
Federal Funds Purchased	$ 353,280	$ 260,070
Securities Sold under Agreements to Repurchase	42,372	47,794
Federal Funds Purchased and Securities Sold under Agreements to Repurchase, Total	395,652	307,864
Debt Instrument [Line Items]
Senior Notes	300,000	300,000
Subordinated Debt	300,000	300,000
Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net	(7,190)	(7,484)
Long-term Debt	592,629	594,276
TotalShortTermLongTermExcludingFHLB	988,281	902,140
Federal Funds Purchased	353,280	260,070
Securities Sold under Agreements to Repurchase	42,372	47,794
Federal Funds Purchased and Securities Sold under Agreements to Repurchase	395,652	307,864
Advance from Federal Home Loan Bank	3,010,000	2,855,250
Long-Term Federal Home Loan Bank Advances	414,089	414,122
Federal Home Loan Bank, Advances, Branch of FHLB Bank, Amount of Advances	3,421,762	3,268,094
Debt, Long-Term and Short-Term, Combined Amount	4,410,043	4,170,234
Short-Term Debt	395,652	307,864
Advance from Federal Home Loan Bank [Abstract]
Advance from Federal Home Loan Bank	3,010,000	2,855,250
Long-Term Federal Home Loan Bank Advances	414,089	414,122
Federal Home Loan Bank, Advances, Branch of FHLB Bank, Amount of Advances	3,421,762	3,268,094
Debt, Long-Term and Short-Term, Combined Amount	4,410,043	4,170,234
Fair Value Hedging [Member]
Debt Instrument [Line Items]
Subordinated Debt	(181)	1,760
Advance from Federal Home Loan Bank	(2,327)	(1,278)
Advance from Federal Home Loan Bank [Abstract]
Advance from Federal Home Loan Bank	$ (2,327)	$ (1,278)