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Supplemental Disclosures about Oil and Natural Gas Producing Properties (unaudited) - Narrative (Details) (USD $) | 12 Months Ended |
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Jun. 30, 2014 Boe | Jun. 30, 2013 Boe | Jun. 30, 2012 Boe | Jun. 30, 2011 Boe
Reserve Quantities [Line Items] |  |  |  |  |  |
Oil and natural gas property costs attributable to the recognition of asset retirement obligations | $ 66,976 |  | $ 65,575 |  | $ 93,522 |
Period Considered for Unweighted Arithmetic Average for Determining Reserve Volumes and Values | 12 months |  |  |  |  |
Proved Developed and Undeveloped Reserves Energy Equivalents, Net | 13,289,510 |  | 13,766,440 |  | 13,441,116 | 13,847,462
Period Considered for Determining Unweighted Arithmetic Average of First Day of Month, Commodity Prices | 12 months |  |  |  |  |
Proved Developed and Undeveloped Reserves Energy Equivalents Revisions of Previous Estimates Increase (Decrease) | (247,350) | [1] | 2,806,181 | [2] | (344,440) |
Proved Developed and Undeveloped Reserves Energy Equivalents Production | 177,742 |  | 226,819 |  | 208,155 |
Proved Developed and Undeveloped Reserves Energy Equivalents Sales of Minerals in Place | 184,722 |  | 2,254,038 |  |  |
[1] | Significant reserve revisions occurred in the Delhi Field during fiscal 2014. As a result of an adverse fluid release event in the Field, certain oil reserves were reclassified from proved to an unproved category based on the operator's decision to defer CO2 injections in certain parts of the Field. There was a positive revision to estimated proved reserves of natural gas liquids and natural gas as a result of an improved design for the gas plant in the Delhi Field. The plant is expected to significantly increase recoveries of these products, particularly natural gas, which was not previously planned to be extracted from the injection volumes.
[2] | A significant upward reserve revision occurred in the Delhi Field during fiscal 2013 as a result of (1) revised geological maps based on production results and acquired seismic data, (2) inclusion of an additional reservoir with similar features, production history and suitability for EOR, and (3) inclusion of natural gas processing at Delhi.

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- Definition Amount of asset retirement obligations incurred during the period, net of certain increases or decreases in the amount of the asset retirement obligation during the current period that may include changes in the amount or timing of the estimated cash flows associated with the settlement of the obligation. + References No definition available. + Details
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