Note 11 - Income Taxes (Details Textual) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Operating Loss Carryforwards, Total	$ 37,800,000
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	$ 300,000	$ 400,000
Domestic Tax Authority [Member] | Canada Revenue Agency [Member]
Open Tax Year	2015 2016 2017 2018