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Dehli Field Litigation Settlement (Details) - USD ($) |  | 12 Months Ended
--- | --- | ---
Jun. 24, 2016 | Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2016
Loss Contingencies [Line Items] |  |  |  |
Delhi field litigation settlement gain |  | $ 0 | $ 0 | $ 28,096,500
Fair value of litigation settlement |  | $ 0 | $ 0 | $ 596,500
Dehli Field Litigation | Denbury Resources, Inc |  |  |  |
Loss Contingencies [Line Items] |  |  |  |
Delhi field litigation settlement gain | $ 28,100,000 |  |  |
Proceeds from litigation | $ 27,500,000 |  |  |
Working interest in Mengal Sand Interval | 23.90% |  |  |
Fair value of litigation settlement | $ 596,500 |  |  |
Overriding royalty interest in Holt-Bryant | 0.2226% |  |  |
Dehli Field Litigation | Denbury Resources, Inc | Level 2 |  |  |  |
Loss Contingencies [Line Items] |  |  |  |
Fair value of litigation settlement | $ 596,500 |  |  |

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