Note 13 - Acquisitions - Preliminary Purchase Price Allocation (Details) (Parentheticals) - Mines Management [Member] - $ / shares		1 Months Ended
Sep. 13, 2016	Sep. 30, 2016
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares	8,309,006	8,309,006
Business Acquisition, Share Price	$ 5.79

Number of shares of equity interests issued or issuable to acquire entity.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)(4)
-URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration