Note 16 - Acquisitions - Preliminary Purchase Price Allocation (Details) - Klondex Mines Ltd [Member] $ in Thousands	Jul. 20, 2018 USD ($)
Payments to Acquire Businesses, Gross	$ 161,704
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable	242,389
Hecla warrants issued	9,830
Total consideration	413,923
Cash	12,874
Accounts receivable	3,453
Inventory - supplies	6,565
Inventory - finished goods, in-process material and stockpiled ore	10,075
Other current assets	2,583
Properties, plants, equipment and mineral interests	510,015
Non-current investments	1,596
Non-current restricted cash and investments	9,504
Total assets	556,665
Accounts payable and accrued liabilities	17,799
Accrued payroll and related benefits	8,245
Accrued taxes	421
Lease liability	2,080
Debt	35,086
Asset retirement obligation	19,571
Deferred tax liability	59,540
Total liabilities	142,742
Net assets	$ 413,923