Quarterly report pursuant to Section 13 or 15(d)

Sale of Amadeus Basin Assets (Details)

v2.4.1.9
Sale of Amadeus Basin Assets (Details)
9 Months Ended 0 Months Ended 9 Months Ended 9 Months Ended 0 Months Ended
Mar. 31, 2015
USD ($)
Mar. 31, 2014
USD ($)
Mar. 31, 2015
Central Petroleum Limited
Mar. 31, 2014
Amadeus Basin
AUD
Mar. 31, 2015
Amadeus Basin
Mar. 31, 2015
Amadeus Basin
Maximum
AUD
Mar. 31, 2015
Amadeus Basin
Palm Valley
Mar. 31, 2014
Amadeus Basin
Central Petroleum Limited
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]                
Amount paid in exchange for assets $ 0us-gaap_ProceedsFromSaleOfOilAndGasPropertyAndEquipment $ 13,859,000us-gaap_ProceedsFromSaleOfOilAndGasPropertyAndEquipment   20,000,000us-gaap_ProceedsFromSaleOfOilAndGasPropertyAndEquipment
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= mpet_AmadeusBasinMember
       
Customary purchase price adjustments       800,000mpet_ProceedsfromDivestitureofBusinessesCustomaryPurchasePriceAdjustments
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= mpet_AmadeusBasinMember
       
Shares issued during period for acquisitions               39,500,000.0us-gaap_StockIssuedDuringPeriodSharesAcquisitions
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= mpet_AmadeusBasinMember
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= mpet_CentralPetroleumLimitedMember
Ownership percentage     11.00%us-gaap_EquityMethodInvestmentOwnershipPercentage
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= mpet_CentralPetroleumLimitedMember
         
Royalty rate             25.00%mpet_OilandGasPropertyRoyaltyRate
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= mpet_AmadeusBasinMember
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= mpet_PalmValleyMember
 
AUD/Gigajoule gas price trigger for first ten years             5.00mpet_OilandGasPropertyRoyaltyRateTriggerGasPriceforFirstTenYears
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= mpet_AmadeusBasinMember
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= mpet_PalmValleyMember
 
AUD/Gigajoule gas price trigger for following five years             6.00mpet_OilandGasPropertyRoyaltyRateTriggerGasPriceforFollowingFiveYears
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= mpet_AmadeusBasinMember
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= mpet_PalmValleyMember
 
Discount rate         10.00%mpet_OilandGasPropertyDiscountRate
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= mpet_AmadeusBasinMember
     
Bonus discharge amount           7,000,000.0mpet_OilandGasPropertyBonusDischargeAmount
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= mpet_AmadeusBasinMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember