Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Accumulated depreciation	$ 18,325	$ 18,243
Accumulated amortization, intangible assets	$ 355	$ 341
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	40,000,000	40,000,000
Common stock, shares issued (in shares)	31,272,303	31,227,300
Common stock, shares outstanding (in shares)	30,296,297	30,263,791