Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Statement Of Financial Position [Abstract]
Available-for-sale, amortized cost	$ 687,404	$ 697,094
Equity securities, cost	$ 12,081	$ 11,419
Common stock, par value (in dollars per share)	$ 0.625	$ 0.625
Common stock, shares authorized (in shares)	10,000,000	10,000,000
Common stock, shares issued (in shares)	3,776,580	3,760,315
Common stock, shares outstanding (in shares)	3,567,894	3,553,629
Treasury stock, shares (in shares)	208,686	206,686