Note 22 - Segment Reporting - Summary of Segment Reporting Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019		Dec. 31, 2019
Revenues	$ 4,384	$ 8,567
Cost of revenues	3,485	8,125
Total operating expenses	3,175	1,180
Depreciation and amortization expense included in total operating expenses	207	38
Operating (loss)/income	(2,276)	(738)
Change in fair value of warrant liabilities	46	(350)
Net (loss)/income	(2,310)	(1,140)
Expenditure for long-term assets	302
Total assets	18,494	18,551		$ 18,551
Corporate, Non-Segment [Member]
Revenues	645
Cost of revenues
Total operating expenses	2,148	452	[1]
Depreciation and amortization expense included in total operating expenses	1	15
Operating (loss)/income	(1,503)	(452)
Change in fair value of warrant liabilities	46	(350)
Net (loss)/income	(1,519)	(801)
Expenditure for long-term assets
Total assets	21,940	21,338
Intersegment Eliminations [Member]
Revenues
Cost of revenues
Total operating expenses
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	(21,991)	(22,079)
Internet Ad [Member] | Operating Segments [Member]
Revenues	3,236	8,567
Cost of revenues	3,110	8,125
Total operating expenses	1,022	705
Depreciation and amortization expense included in total operating expenses	206	23
Operating (loss)/income	(896)	(263)
Change in fair value of warrant liabilities
Net (loss)/income	(893)	(315)
Expenditure for long-term assets
Total assets	11,521	13,332
Ecommerce O2O Ad and Marketing Services [Member] | Operating Segments [Member]
Revenues	503
Cost of revenues	375
Total operating expenses	4	18
Depreciation and amortization expense included in total operating expenses
Operating (loss)/income	124	(18)
Change in fair value of warrant liabilities
Net (loss)/income	103	(19)
Expenditure for long-term assets
Total assets	2,844	2,075
Blockchain Technology [Member] | Operating Segments [Member]
Revenues
Cost of revenues
Total operating expenses	1	5
Depreciation and amortization expense included in total operating expenses
Operating (loss)/income	(1)	(5)
Change in fair value of warrant liabilities
Net (loss)/income	(1)	(5)
Expenditure for long-term assets	302
Total assets	$ 4,180	$ 3,885

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