Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - $ / shares	Mar. 31, 2018	Dec. 31, 2017
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred stock, authorized (in shares)	250,000	250,000
Preferred stock, issued (in shares)	0	0
Preferred stock, oustanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, authorized (in shares)	20,000,000	20,000,000
Common stock, issued (in shares)	13,936,957	13,918,168
Common stock, outstanding (in shares)	13,936,957	13,918,168