Note 2 - Variable Interest Entities - Consolidated VIEs' Financial Performance (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenues	$ 14,551		$ 10,416		$ 22,947	$ 14,800
Cost of revenues	(14,769)		(10,118)		(23,882)	(13,603)
Total operating expenses	(8,061)		(1,318)		(9,159)	(4,493)
Net (loss)/income	(3,646)	$ 687	(970)	$ (2,310)	(2,959)	(3,280)
Variable Interest Entity, Primary Beneficiary [Member]
Revenues	12,671		9,612		20,618	12,548
Cost of revenues	(14,394)		(9,477)		(23,132)	(12,322)
Total operating expenses	(322)		(648)		(712)	(1,392)
Net (loss)/income	$ (2,126)		$ (509)		$ (3,407)	$ (1,160)