Note 15 - Unaudited Quarterly Results - Schedule of Quarterly Financial Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net sales	$ 84,522	$ 84,190	$ 79,980	$ 70,098	$ 65,752	$ 65,266	$ 60,052	$ 54,792	$ 51,643	$ 50,800	$ 47,625	$ 43,170	$ 318,790	$ 245,862	$ 193,237
Income/(loss) from operations	(3,103)	3,760	231	(2,886)	4,876	3,535	(5,346)	(3,317)	1,890	44	(3,410)	(3,410)	(1,998)	(253)	(4,886)
Net Income/(loss)	(3,298)	3,547	153	(3,590)	4,633	3,067	(5,661)	(3,422)	1,757	(97)	(3,501)	(3,521)	$ (3,188)	$ (1,383)	$ (5,361)
Net Income/(loss) attributable to common stockholders	$ (3,298)	$ 3,547	$ 153	$ (3,590)	$ 4,633	$ 3,067	$ (5,661)	$ (3,422)	$ 1,757	$ (97)	$ (3,501)	$ (3,521)
Basic earnings/(loss) per common share (in dollars per share)	$ (0.08)	$ 0.09	$ 0.00	$ (0.10)	$ 0.13	$ 0.09	$ (0.16)	$ (0.10)	$ 0.05	$ (0.00)	$ (0.10)	$ (0.10)	$ (0.08)	$ (0.04)	$ (0.15)
Diluted earnings/(loss) per common share (in dollars per share)	$ (0.08)	$ 0.09	$ 0.00	$ (0.10)	$ 0.12	$ 0.08	$ (0.16)	$ (0.10)	$ 0.05	$ (0.00)	$ (0.10)	$ (0.10)	$ (0.08)	$ (0.04)	$ (0.15)