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Note 1 - Organization and Business (Details Textual) shares in Millions, $ in Millions |  |  |  | 1 Months Ended | 6 Months Ended | 12 Months Ended |
--- | --- | --- | --- | --- | --- | --- | ---
Nov. 10, 2017 a | Sep. 29, 2014 | Nov. 29, 2010 USD ($) a shares | Sep. 30, 2012 a | Jun. 30, 2018 USD ($) | Jun. 30, 2018 USD ($) | Jan. 08, 2015 USD ($)
Number of Wholly Owned Subsidiaries |  |  |  |  | 2 | 2 |
Sale of Stock, Number of Shares Issued in Transaction | shares |  |  | 1.6 |  |  |  |
The Joint Venture Company [Member] |  |  |  |  |  |  |
Exploration Budget |  |  |  |  | $ 9.1 |  |
Exploration Budget, Amount Spent |  |  |  |  | $ 4.6 |  |
Royal Gold [Member] | The Joint Venture Company [Member] |  |  |  |  |  |  |
Initial Investment to Fund Exploration Activity |  |  |  |  |  |  | $ 5.0
Payments to Acquire Interest in Joint Venture |  |  |  |  |  | $ 31.7 |
Percentage Ownership in Company |  |  |  |  | 40.00% | 40.00% |
Unpatented Mining Claims from the State of Alaska for Gold and Minerals [Member] |  |  |  |  |  |  |
Acreage of Unpatented Mining Claims | a |  |  | 18,021 |  |  |  |
Unpatented State of Alaska Mining Claims [Member] | The Joint Venture Company [Member] |  |  |  |  |  |  |
Number of Mining Claims Acquired | 541 |  |  |  |  |  |
Mining Claims Acquired, Area | a | 84,840 |  |  |  |  |  |
Production Royalty Percentage | 3.00% |  |  |  |  |  |
Native Village of Tetlin Land [Member] |  |  |  |  |  |  |
Percentage of Leasehold Interest |  |  | 100.00% |  |  |  |
Leasehold Interest Acreage | a |  |  | 675,000 |  |  |  |
Contango [Member] |  |  |  |  |  |  |
Parent Contribution |  |  | $ 3.5 |  |  |  |
Royal Gold [Member] |  |  |  |  |  |  |
Overriding Royalty Interest |  |  | 3.00% |  |  |  |
Royal Gold [Member] | The Tetlin Lease and Unpatented State of Alaska Mining Claims [Member] | JEX [Member] |  |  |  |  |  |  |
Royalty Interest Sold |  | 3.00% |  |  |  |  |
Royal Gold [Member] | Unpatented State of Alaska Mining Claims [Member] | JEX [Member] |  |  |  |  |  |  |
Royalty Interest Sold |  | 2.00% |  |  |  |  |
JEX [Member] |  |  |  |  |  |  |
Overriding Royalty Interest |  |  |  | 2.00% | 3.00% | 3.00% |
JEX [Member] | Unpatented State of Alaska Mining Claims [Member] |  |  |  |  |  |  |
Number of Mining Claims Acquired |  |  |  | 474 |  |  |
Mining Claims Acquired, Area | a |  |  |  | 71,896 |  |  |
Production Royalty Percentage |  |  |  | 2.00% |  |  |

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