Note 15 - Common stock warrants: Schedule of Series B and Series D common stock warrants (Details) - shares		6 Months Ended	12 Months Ended
		Jun. 30, 2018	Dec. 31, 2017
Series B
Warrants Outstanding, Starting Balance		0	4,500
Warrants Issued		0	0
Warrants Exercised		0	(4,500)
Warrants Outstanding, Ending Balance		87,456	0
Common Stock Warrants Reinstated	[1]	87,456
Series D
Warrants Outstanding, Starting Balance		6,666,007	8,206,390
Warrants Issued		0	0
Warrants Exercised		(379,436)	(1,540,383)
Warrants Outstanding, Ending Balance		6,316,115	6,666,007
Common Stock Warrants Reinstated	[1]	29,544
B and D Total
Warrants Outstanding, Starting Balance		6,666,007	8,210,890
Warrants Issued		0	0
Warrants Exercised		(379,436)	(1,544,883)
Warrants Outstanding, Ending Balance		6,403,571	6,666,007
Common Stock Warrants Reinstated	[1]	117,000

[1] See Note 5.