Note 15 - 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, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Total revenues	$ 22,562	$ 21,914	$ 20,568	$ 20,541	$ 19,725	$ 20,213	$ 21,119	$ 24,737
Costs of revenues	9,059	8,715	7,832	7,867	9,721	10,683	10,917	11,482	$ 33,474	$ 42,803
Net loss	$ (1,330)	$ (687)	$ (710)	$ (2,691)	$ (3,114)	$ (2,082)	$ (2,096)	$ (424)	$ (5,418)	$ (7,716)
Basic (in dollars per share)	$ (0.04)	$ (0.02)	$ (0.02)	$ (0.08)	$ (0.10)	$ (0.06)	$ (0.07)	$ (0.01)	$ (0.17)	$ (0.24)
Diluted (in dollars per share)	$ (0.04)	$ (0.02)	$ (0.02)	$ (0.08)	$ (0.10)	$ (0.06)	$ (0.07)	$ (0.01)	$ (0.17)	$ (0.24)