Note 9 - Commitments and Off-balance Sheet Risk - Exposure to Credit Losses (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Contractual amounts of financial instruments with off-balance sheet risk	$ 2,037,112	$ 2,101,302
Standby Letters of Credit [Member]
Contractual amounts of financial instruments with off-balance sheet risk	27,177	26,491
Unused lines of Credit [Member] \| Commercial Portfolio Segment [Member]
Contractual amounts of financial instruments with off-balance sheet risk	1,474,577	1,488,782
Unused lines of Credit [Member] \| One to Four Family Mortgages [Member]
Contractual amounts of financial instruments with off-balance sheet risk	86,113	84,298
Unused lines of Credit [Member] \| Credit Card Lines of Credit [Member]
Contractual amounts of financial instruments with off-balance sheet risk	181,546	172,273
Unused lines of Credit [Member] \| Consumer Other Financing Receivable 1 [Member]
Contractual amounts of financial instruments with off-balance sheet risk	33,852	33,892
Loan Origination Commitments [Member]
Contractual amounts of financial instruments with off-balance sheet risk	$ 233,847	$ 295,566