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) | 2,381,440 us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod |  |
Restricted stock awards |  |  |
Stock-Based Compensation |  |  |
Granted (in shares) |  | 20,000 us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod / us-gaap_AwardTypeAxis = us-gaap_RestrictedStockMember |
Phantom share units |  |  |
Stock-Based Compensation |  |  |
Granted (in shares) |  | 2,361,440 us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod / us-gaap_AwardTypeAxis = us-gaap_PhantomShareUnitsPSUsMember |
Antero |  |  |
Additional disclosures |  |  |
Unrecognized equity-based compensation expense | 66.7 us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions / us-gaap_RelatedPartyTransactionsByRelatedPartyAxis = am_AnteroResourcesCorporationMember |  |
Antero | Profits interests awards |  |  |
Additional disclosures |  |  |
Unrecognized equity-based compensation expense | 37.0 us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions / us-gaap_AwardTypeAxis = am_MembershipInterestsAwardsMember / us-gaap_RelatedPartyTransactionsByRelatedPartyAxis = am_AnteroResourcesCorporationMember |  |
Antero LTIP [Member] |  |  |
Additional disclosures |  |  |
Unrecognized equity-based compensation expense | 104.8 us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions / us-gaap_RelatedPartyTransactionsByRelatedPartyAxis = am_AnteroLtipMember |  |
Midstream LTIP | Restricted stock awards |  |  |
Stock-Based Compensation |  |  |
Granted (in shares) |  | 20,000 us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod / us-gaap_AwardTypeAxis = us-gaap_RestrictedStockMember / us-gaap_RelatedPartyTransactionsByRelatedPartyAxis = am_MidstreamLongTermIncentivePlanMember |
Midstream LTIP | Phantom share units |  |  |
Stock-Based Compensation |  |  |
Granted (in shares) |  | 2,361,440 us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod / us-gaap_AwardTypeAxis = us-gaap_PhantomShareUnitsPSUsMember / us-gaap_RelatedPartyTransactionsByRelatedPartyAxis = am_MidstreamLongTermIncentivePlanMember |
Predecessor |  |  |
Additional disclosures |  |  |
Equity-based compensation expense | 8.6 us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_StatementScenarioAxis = us-gaap_PredecessorMember |  | $ 15.9 us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_StatementScenarioAxis = us-gaap_PredecessorMember

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- Definition Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB TOPIC 14.F) -URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1)(i) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 14 -Section F + Details
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- Definition Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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