Quarterly report pursuant to Section 13 or 15(d)

Discontinued Operations (Assets and Liabilities) (Details)

v2.4.1.9
Discontinued Operations (Assets and Liabilities) (Details) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 9 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Mar. 31, 2015
Mar. 31, 2014
Apr. 15, 2014
Consideration          
Reclassification of foreign currency translation gains to earnings upon sale of foreign subsidiary $ 0us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationReclassificationAdjustmentFromAOCIRealizedUponSaleOrLiquidationNetOfTax $ 6,049us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationReclassificationAdjustmentFromAOCIRealizedUponSaleOrLiquidationNetOfTax $ 0us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationReclassificationAdjustmentFromAOCIRealizedUponSaleOrLiquidationNetOfTax $ 6,049us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationReclassificationAdjustmentFromAOCIRealizedUponSaleOrLiquidationNetOfTax  
Gain on disposal of discontinued operations, net of tax 0us-gaap_DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax 30,182us-gaap_DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax 0us-gaap_DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax 30,182us-gaap_DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax  
Sale Deed          
Assets and liabilities sold          
Property and equipment, net   (10,100)us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipment
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= mpet_SaleDeedMember
  (10,100)us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipment
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= mpet_SaleDeedMember
 
Deferred income taxes   (7,217)us-gaap_DisposalGroupIncludingDiscontinuedOperationDeferredTaxAssetsNoncurrent
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= mpet_SaleDeedMember
  (7,217)us-gaap_DisposalGroupIncludingDiscontinuedOperationDeferredTaxAssetsNoncurrent
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= mpet_SaleDeedMember
 
Goodwill allocated to disposal group   (1,000)us-gaap_DisposalGroupIncludingDiscontinuedOperationGoodwill1
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= mpet_SaleDeedMember
  (1,000)us-gaap_DisposalGroupIncludingDiscontinuedOperationGoodwill1
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= mpet_SaleDeedMember
 
Asset retirement obligations   4,457mpet_DisposalGroupIncludingDiscontinuedOperationAssetRetirementObligation
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= mpet_SaleDeedMember
  4,457mpet_DisposalGroupIncludingDiscontinuedOperationAssetRetirementObligation
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= mpet_SaleDeedMember
 
Other assets and liabilities, net   1,178mpet_DisposalGroupIncludingDiscontinuedOperationsOtherAssetsLiabilitiesNet
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= mpet_SaleDeedMember
  1,178mpet_DisposalGroupIncludingDiscontinuedOperationsOtherAssetsLiabilitiesNet
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= mpet_SaleDeedMember
 
Total assets and liabilities of discontinued operations   (12,682)mpet_DiscontinuedOperationsandDisposalGroupsAssetsLiabilities
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= mpet_SaleDeedMember
  (12,682)mpet_DiscontinuedOperationsandDisposalGroupsAssetsLiabilities
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= mpet_SaleDeedMember
 
Consideration          
Cash consideration   13,859mpet_DisposalGroupIncludingDiscontinuedOperationConsiderationCash
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= mpet_SaleDeedMember
  13,859mpet_DisposalGroupIncludingDiscontinuedOperationConsiderationCash
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= mpet_SaleDeedMember
4,624mpet_DisposalGroupIncludingDiscontinuedOperationConsiderationCash
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= mpet_SaleDeedMember
Stock of Central   19,147mpet_DisposalGroupIncludingDiscontinuedOperationConsiderationEquity
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= mpet_SaleDeedMember
  19,147mpet_DisposalGroupIncludingDiscontinuedOperationConsiderationEquity
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= mpet_SaleDeedMember
 
Total consideration   37,630us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= mpet_SaleDeedMember
  37,630us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= mpet_SaleDeedMember
 
Reclassification of foreign currency translation gains to earnings upon sale of foreign subsidiary       6,049us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationReclassificationAdjustmentFromAOCIRealizedUponSaleOrLiquidationNetOfTax
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= mpet_SaleDeedMember
 
Transaction costs       (815)mpet_DisposalGroupincludingDiscontinuedOperationsTransactionCosts
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= mpet_SaleDeedMember
 
Gain on disposal of discontinued operations, net of tax       $ 30,182us-gaap_DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= mpet_SaleDeedMember