Condensed Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 1,175	$ 1,411
Accumulated depreciation	25,993	26,528
Accumulated amortization	$ 6,611	$ 6,608
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)	24,843,668	24,825,891
Common stock outstanding (in shares)	24,186,824	24,170,585