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Dehli Field Litigation Settlement (Details) - USD ($) |  |  | 12 Months Ended
--- | --- | --- | ---
Jul. 01, 2016 | Jun. 24, 2016 | Jun. 30, 2016 | Jun. 30, 2015 | Jun. 30, 2014
Loss Contingencies [Line Items] |  |  |  |  |
Delhi field litigation settlement gain |  |  | $ 28,096,500 | $ 0 | $ 0
Fair value of litigation settlement |  |  | 596,500 | $ 0 | $ 0
Dehli Field Litigation |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |
Delhi field litigation settlement gain |  |  | $ 28,100,000 |  |
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 |  |  |
Dehli Field Litigation | Denbury Resources, Inc | Subsequent Event |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |
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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