Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Statement Of Financial Position [Abstract]
Available-for-sale, amortized cost	$ 396,168	$ 362,742
Held-to-maturity, fair value	$ 0	$ 151
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)	3,576,270	3,524,363
Common stock, shares outstanding (in shares)	3,411,701	3,359,794
Treasury stock, shares (in shares)	164,569	164,569