Note 2 - Variable Interest Entities - Consolidated VIEs' Financial Performance (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenues	$ 10,416		$ 15,453		$ 14,800	$ 24,020
Cost of revenues	(10,118)		(15,087)		(13,603)	(23,212)
Total operating expenses	(1,318)		(1,588)		(4,493)	(2,768)
Net loss before allocation to noncontrolling interests	970	$ 2,310	382	$ 1,140	3,280	1,522
Variable Interest Entity, Primary Beneficiary [Member]
Revenues	9,612		15,453		12,548	24,020
Cost of revenues	(9,477)		(15,087)		(12,322)	(23,212)
Total operating expenses	(648)		(1,151)		(1,392)	(1,862)
Net loss before allocation to noncontrolling interests	$ (509)		$ (764)		$ (1,160)	$ (1,086)