Note 2 - Securities - Debt Securities by Maturity (Details) - USD ($)	Sep. 30, 2022	Dec. 31, 2021
Due in 2022, Weighted Average Yield	1.35%
Due in 2022, Amortized Cost	$ 3,739,000
Due in 2022, Fair Value	$ 3,732,000
Due in 2023 through 2027, Weighted Average Yield	1.15%
Due in 2023 through 2027, Amortized Cost	$ 267,809,000
Due in 2023 through 2027, Fair Value	$ 242,952,000
Due in 2028 through 2032, Weighted Average Yield	1.86%
Due in 2028 through 2032, Amortized Cost	$ 316,237,000
Due in 2028 through 2032, Fair Value	$ 264,643,000
Due in 2033 and beyond, Weighted Average Yield	2.58%
Due in 2033 and beyond, Amortized Cost	$ 47,429,000
Due in 2033 and beyond, Fair Value	$ 38,515,000
Total available for sale securities, weighted average yield	1.64%
Total available for sale securities, Amortized Cost	$ 674,725,000	$ 597,463,000
Securities available for sale	$ 582,999,000	592,743,000
Collateralized Mortgage-Backed Securities [Member]
No single maturity, weighted average yield	2.09%
No single maturity, amortized cost	$ 39,011,000
No single maturity, fair value	32,657,000
Total available for sale securities, Amortized Cost	39,011,000	41,906,000
Securities available for sale	$ 32,657,000	41,803,000
Other Debt and Equity Securities [Member]
No single maturity, weighted average yield	4.33%
No single maturity, amortized cost	$ 500,000
No single maturity, fair value	500,000
Total available for sale securities, Amortized Cost	500,000	500,000
Securities available for sale	$ 500,000	$ 500,000