Condensed Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 1,610	$ 1,569
Accumulated depreciation	25,334	24,542
Accumulated amortization	$ 6,313	$ 5,902
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)	24,777,001	23,800,924
Common stock outstanding (in shares)	24,132,910	23,446,035