CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (Parentheticals) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Issuance of common stock to non-employee directors (in shares)	5,556	5,814	5,922
Dividends paid (in dollars per share)	$ 0.72	$ 0.72	$ 0.72
Stock Options
Exercise of stock options (in shares)	0	10,250	26,500