Condensed Consolidated Statements of Changes in Shareholders' Equity (Unaudited) (Parentheticals) - $ / shares	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Common Stock [Member]
Dividend reinvestment plan (in shares)	39,612	38,195
Stock option exercises (in shares)	20,000	31,249
Stock grants to directors (in shares)	11,712	13,000
Share repurchase program (in shares)		167,878
Employee stock purchase plan (in shares)	682	773
Retained Earnings [Member]
Cash dividends per common share (in dollars per share)	$ 0.36	$ 0.32
Cash dividends per common share (in dollars per share)	$ 0.36	$ 0.32