Note 21 - Segment Reporting - Summary of Segment Reporting Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019		Mar. 31, 2018		Dec. 31, 2018
Revenues	$ 8,567		$ 8,260
Cost of revenues	8,125		7,659
Total operating expenses	1,180		2,146
Depreciation and amortization expense included in total operating expenses	38		216
Operating (loss)/income	(738)		(1,545)
Change in fair value of warrant liabilities	(350)		1,474
Net (loss)/income	(1,140)		(570)
Total assets	15,075				$ 16,989
Impairment on long-term investments			(471)
Expenditure for long-term assets			1,649
Operating Segments [Member] | Internet Ad [Member]
Revenues	8,567		8,169
Cost of revenues	8,125		7,621
Total operating expenses	705		1,622
Depreciation and amortization expense included in total operating expenses	23		197
Operating (loss)/income	(263)		(1,074)
Change in fair value of warrant liabilities
Net (loss)/income	(315)		(1,073)
Total assets	11,587				12,756
Impairment on long-term investments
Expenditure for long-term assets			448
Operating Segments [Member] | TV Ad [Member]
Revenues			91
Cost of revenues			38
Total operating expenses	18		22
Depreciation and amortization expense included in total operating expenses
Operating (loss)/income	(18)		31
Change in fair value of warrant liabilities
Net (loss)/income	(19)		20
Total assets	242				207
Impairment on long-term investments
Expenditure for long-term assets
Operating Segments [Member] | Blockchain Technology [Member]
Revenues
Cost of revenues
Total operating expenses	5
Depreciation and amortization expense included in total operating expenses
Operating (loss)/income	(5)
Change in fair value of warrant liabilities
Net (loss)/income	(5)
Total assets	3,391				3,396
Impairment on long-term investments
Expenditure for long-term assets			1,200
Corporate, Non-Segment [Member]
Revenues			371
Cost of revenues
Total operating expenses	452	[1]	873	[2]
Depreciation and amortization expense included in total operating expenses	15		19
Operating (loss)/income	(452)		(502)
Change in fair value of warrant liabilities	(350)		1,474
Net (loss)/income	(801)		483
Total assets	16,695				17,155
Impairment on long-term investments			(471)
Expenditure for long-term assets			1
Intersegment Eliminations [Member]
Revenues			(371)
Cost of revenues
Total operating expenses			(371)
Depreciation and amortization expense included in total operating expenses
Operating (loss)/income
Change in fair value of warrant liabilities
Net (loss)/income
Total assets	$ (16,840)				$ (16,546)
Impairment on long-term investments
Expenditure for long-term assets

[1] Including approximately US$101,000 share-based compensation expenses.

[2] Including approximately US$75,000 share-based compensation expenses.