Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - $ / shares $ / shares in Thousands	Jun. 30, 2021	Dec. 31, 2020
Preferred stock, par value (in dollars per share)	$ 0	$ 0
Preferred stock, shares authorized (in shares)	1,000,000	1,000,000
Preferred stock, shares issued (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0	$ 0
Common stock, shares authorized (in shares)	40,000,000	40,000,000
Common stock, shares outstanding (in shares)	16,007,185	16,425,136
Common stock, shares issued (in shares)	16,007,185	16,425,136