Note 16 - Selected Quarterly Financial Data (Unaudited) - Selected Quarterly Financial Data (Unaudited) (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, 2020	Dec. 31, 2019
Total revenues	$ 22,367	$ 23,112	$ 21,409	$ 21,158	$ 22,562	$ 21,914	$ 20,568	$ 20,541
Costs of revenues	9,839	9,493	8,946	8,487	9,059	8,715	7,832	7,867
Net loss	$ (33,449)	$ (2,734)	$ (3,652)	$ (528)	$ (1,330)	$ (687)	$ (710)	$ (2,691)	$ (40,363)	$ (5,418)
Basic (in dollars per share)	$ (0.91)	$ (0.08)	$ (0.11)	$ (0.02)	$ (0.04)	$ (0.02)	$ (0.02)	$ (0.08)	$ (1.17)	$ (0.17)
Diluted (in dollars per share)	$ (0.91)	$ (0.08)	$ (0.11)	$ (0.02)	$ (0.04)	$ (0.02)	$ (0.02)	$ (0.08)	$ (1.17)	$ (0.17)