Condensed Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 1,795	$ 1,816
Accumulated depreciation	26,326	26,174
Accumulated amortization	$ 1,033	$ 991
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)	25,404,299	25,053,480
Common stock outstanding (in shares)	24,636,390	24,592,578