Note 23 - Segment Reporting - Summary of Segment Reporting Information (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		Dec. 31, 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
Depreciation and amortization expense included in total operating expenses	14		81				66		508
Operating (loss)/income	(275)		(3,350)				(2,235)		(13,092)
Change in fair value of warrant liabilities	(120)		501				351		1,449
Net (loss)/income	(391)		(2,973)		$ (1,522)	$ (10,124)	(1,913)		(12,963)
Expenditure for long-term assets	760						760		4,191
Total assets	18,960						18,960				$ 16,968
Impairment on goodwill included in total operating expenses									5,289
Impairment on intangible assets included in total operating expenses			1,502						3,380
Impairment on long-term investments									(460)
Net loss	(391)		(2,973)		$ (1,522)	$ (10,124)	(1,913)		(12,963)
Corporate, Non-Segment [Member]
Revenues			(9)						362
Cost of revenues
Total operating expenses	479	[1]	488	[2]			1,350	[3]	1,854	[4]
Depreciation and amortization expense included in total operating expenses	1		17				17		55
Operating (loss)/income	(479)		(497)				(1,350)		(1,492)
Change in fair value of warrant liabilities	(120)		501				351		1,449
Net (loss)/income	(599)		(55)				(999)		(899)
Expenditure for long-term assets									3
Total assets	18,088						18,088				17,155
Impairment on goodwill included in total operating expenses
Impairment on intangible assets included in total operating expenses
Impairment on long-term investments									(460)
Net loss	(599)		(55)				(999)		(899)
Intersegment Eliminations [Member]
Revenues			9						(362)
Cost of revenues
Total operating expenses			9						(362)
Depreciation and amortization expense included in total operating expenses
Operating (loss)/income
Change in fair value of warrant liabilities
Net (loss)/income
Expenditure for long-term assets
Total assets	(18,990)						(18,990)				(16,546)
Impairment on goodwill included in total operating expenses
Impairment on intangible assets included in total operating expenses
Impairment on long-term investments
Net loss
Internet Ad [Member] | Operating Segments [Member]
Revenues	15,508		17,042				39,528		47,731
Cost of revenues	14,616		16,649				37,828		45,822
Total operating expenses	675		3,175				2,525		13,440
Depreciation and amortization expense included in total operating expenses	12		63				47		452
Operating (loss)/income	217		(2,782)				(825)		(11,531)
Change in fair value of warrant liabilities
Net (loss)/income	221		(2,847)				(854)		(11,995)
Expenditure for long-term assets	760						760		437
Total assets	16,256						16,256				12,756
Impairment on goodwill included in total operating expenses									5,289
Impairment on intangible assets included in total operating expenses			1,502						3,380
Impairment on long-term investments
Net loss	221		(2,847)				(854)		(11,995)
TV Ad [Member] | Operating Segments [Member]
Revenues									91
Cost of revenues									38
Total operating expenses	6		28				42		75
Depreciation and amortization expense included in total operating expenses			1						1
Operating (loss)/income	(6)		(28)				(42)		(22)
Change in fair value of warrant liabilities
Net (loss)/income	(6)		(28)				(42)		(22)
Expenditure for long-term assets
Total assets	223						223				207
Impairment on goodwill included in total operating expenses
Impairment on intangible assets included in total operating expenses
Impairment on long-term investments
Net loss	(6)		(28)				(42)		(22)
Blockchain Technology [Member] | Operating Segments [Member]
Revenues
Cost of revenues
Total operating expenses	7		43				18		47
Depreciation and amortization expense included in total operating expenses							2
Operating (loss)/income	(7)		(43)				(18)		(47)
Change in fair value of warrant liabilities
Net (loss)/income	(7)		(43)				(18)		(47)
Expenditure for long-term assets									3,751
Total assets	3,383						3,383				$ 3,396
Impairment on goodwill included in total operating expenses
Impairment on intangible assets included in total operating expenses
Impairment on long-term investments
Net loss	$ (7)		$ (43)				$ (18)		$ (47)

[1] Including approximately US$104,000 share-based compensation expenses.

[2] Including approximately US$64,000 share-based compensation expenses.

[3] Including approximately US$307,000 share-based compensation expenses.

[4] Including approximately US$215,000 share-based compensation expenses