Note 3 - Income Taxes (Details Textual) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Jul. 20, 2018
Deferred Tax Liabilities, Net, Total	$ 156,300
Income Tax Expense (Benefit), Total	(7,216)	$ 768
Klondex Mines Ltd [Member]
Deferred Tax Liabilities, Net, Total			$ 60,200
Income Tax Expense (Benefit), Total	(2,500)
Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Deferred Tax Liabilities, Net, Total	51,600
Foreign Tax Authority [Member] | Canada Revenue Agency [Member]
Deferred Tax Liabilities, Net, Total	107,800
Foreign Tax Authority [Member] | Mexican Tax Authority [Member]
Deferred Tax Liabilities, Net, Total	$ 3,100