Note 2 - Variable Interest Entities - Consolidated VIEs' Financial Performance (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues	$ 15,508	$ 17,042			$ 39,528	$ 47,822
Cost of revenues	(14,616)	(16,649)			(37,828)	(45,860)
Total operating expenses	1,167	3,743			3,935	15,054
Net loss for the period	(391)	(2,973)	$ (1,522)	$ (10,124)	(1,913)	(12,963)
VIEs [Member]
Revenues	15,503	17,039			39,523	47,812
Cost of revenues	(14,616)	(16,649)			(37,828)	(45,860)
Total operating expenses	(545)	(1,520)			(2,407)	(11,545)
Net loss for the period	$ 344	$ (1,197)			$ (742)	$ (10,058)