Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Statement Of Financial Position [Abstract]
Available-for-sale, amortized cost	$ 360,472	$ 353,249
Equity securities, cost	$ 6,242	$ 10,079
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)	3,672,125	3,648,649
Common stock, shares outstanding (in shares)	3,507,556	3,484,080
Treasury stock, shares (in shares)	164,569	164,569