Annual report pursuant to Section 13 and 15(d)

Equity Based Compensation (Details)

v2.4.1.9
Equity Based Compensation (Details) (USD $)
In Millions, except Share data, unless otherwise specified
12 Months Ended 0 Months Ended 12 Months Ended
Dec. 31, 2014
Nov. 12, 2014
Dec. 31, 2013
Additional disclosures      
Weighted average period for recognizing unrecognized stock-based compensation expense 3 years 9 months 18 days    
Stock-Based Compensation      
Granted (in shares) 2,381,440us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod    
Restricted stock awards      
Stock-Based Compensation      
Granted (in shares)   20,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
 
Phantom share units      
Stock-Based Compensation      
Granted (in shares)   2,361,440us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_PhantomShareUnitsPSUsMember
 
Antero      
Additional disclosures      
Unrecognized equity-based compensation expense 66.7us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= am_AnteroResourcesCorporationMember
   
Antero | Profits interests awards      
Additional disclosures      
Unrecognized equity-based compensation expense 37.0us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions
/ us-gaap_AwardTypeAxis
= am_MembershipInterestsAwardsMember
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= am_AnteroResourcesCorporationMember
   
Antero LTIP [Member]      
Additional disclosures      
Unrecognized equity-based compensation expense 104.8us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= am_AnteroLtipMember
   
Midstream LTIP | Restricted stock awards      
Stock-Based Compensation      
Granted (in shares)   20,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= am_MidstreamLongTermIncentivePlanMember
 
Midstream LTIP | Phantom share units      
Stock-Based Compensation      
Granted (in shares)   2,361,440us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_PhantomShareUnitsPSUsMember
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= am_MidstreamLongTermIncentivePlanMember
 
Predecessor      
Additional disclosures      
Equity-based compensation expense 8.6us-gaap_AllocatedShareBasedCompensationExpense
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember
  $ 15.9us-gaap_AllocatedShareBasedCompensationExpense
/ us-gaap_StatementScenarioAxis
= us-gaap_PredecessorMember