Note 5 - Loans and Leases - Classifications of Loans and Leases (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Jun. 30, 2024	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022
Notes receivable, gross	$ 1,795,726		$ 1,687,137
Allowance for credit losses on loans	(19,630)	$ (18,975)	(18,806)	$ (18,757)	$ (18,350)	$ (17,149)
Unearned lease revenue	(1,940)		(2,039)
Loans and leases, net	1,774,156		1,666,292
Commercial Portfolio Segment [Member]
Allowance for credit losses on loans	(2,544)	(2,181)	(1,850)	(1,866)	(2,361)	(2,924)
Commercial Portfolio Segment [Member] | Commercial [Member]
Notes receivable, gross	168,633		152,640
Commercial Portfolio Segment [Member] | Municipal [Member]
Notes receivable, gross	113,362		94,724
Commercial Real Estate Portfolio Segment [Member]
Allowance for credit losses on loans	(9,069)	(8,687)	(8,835)	(8,799)	(8,578)	(7,162)
Commercial Real Estate Portfolio Segment [Member] | Non-owner Occupied [Member]
Notes receivable, gross	382,097		337,671
Commercial Real Estate Portfolio Segment [Member] | Owner Occupied [Member]
Notes receivable, gross	296,201		278,293
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Notes receivable, gross	56,273		39,823
Consumer Portfolio Segment [Member]
Allowance for credit losses on loans	(2,346)	(2,368)	(2,391)	(2,135)	(2,514)	(2,827)
Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Notes receivable, gross	54,618		56,640
Consumer Portfolio Segment [Member] | Home Equity Line of Credit [Member]
Notes receivable, gross	57,387		52,348
Consumer Portfolio Segment [Member] | Automobile Loan [Member] | Recourse [Member]
Notes receivable, gross	11,485		10,756
Consumer Portfolio Segment [Member] | Automobile Loan [Member] | Nonrecourse [Member]
Notes receivable, gross	83,905		112,595
Consumer Portfolio Segment [Member] | Direct Financing Lease [Member]
Notes receivable, gross	28,591		33,601
Consumer Portfolio Segment [Member] | Other Loan [Member]
Notes receivable, gross	23,524		16,500
Residential Portfolio Segment [Member]
Allowance for credit losses on loans	(5,639)	$ (5,726)	(5,694)	$ (5,933)	$ (4,847)	$ (4,169)
Residential Portfolio Segment [Member] | Construction Loans [Member]
Notes receivable, gross	29,208		36,536
Residential Portfolio Segment [Member] | Real Estate Loan [Member]
Notes receivable, gross	$ 490,442		$ 465,010