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Equity Based Compensation (Details) (USD $)
3 Months Ended 0 Months Ended 3 Months Ended
Mar. 31, 2015
Nov. 12, 2014
Mar. 31, 2014
Number of units      
Total awarded and unvested at the beginning of the period (in shares) 2,381,440us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber    
Forfeited (in shares) (21,940)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod    
Total awarded and unvested at the end of the period (in shares) 2,359,500us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber    
Weighted average grant date fair value      
Total awarded and unvested at the beginning of the period (in dollars per unit) $ 29.00us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue    
Forfeited (in dollars per unit) $ 29.00us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue    
Total awarded and unvested at the end of the period (in dollars per unit) $ 29.00us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue    
Aggregate intrinsic value      
Total awarded and unvested at the beginning of the period $ 65,490,000us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueNonvested    
Total awarded and unvested at the end of the period 57,076,000us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueNonvested    
Additional disclosures      
Allocated Share-based Compensation Expense 4,600,000us-gaap_AllocatedShareBasedCompensationExpense    
Antero      
Additional disclosures      
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options 62,000,000us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= am_AnteroResourcesCorporationMember
   
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition 3 years 7 months 6 days    
Restricted unit awards      
Number of units      
Granted (in shares)   20,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockUnitsRSUMember
 
Phantom share units      
Number of units      
Granted (in shares)   2,361,440us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_PhantomShareUnitsPSUsMember
 
Various equity based compensation plans | Antero      
Additional disclosures      
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options 183,000,000us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions
/ us-gaap_AwardTypeAxis
= us-gaap_StockCompensationPlanMember
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= am_AnteroResourcesCorporationMember
   
Predecessor      
Additional disclosures      
Allocated Share-based Compensation Expense     $ 1,300,000us-gaap_AllocatedShareBasedCompensationExpense
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember