2.4.0.8100220 - Disclosure - Description of Business and Basis of Presentation - Additional Information (Detail)truefalsefalse1false USDfalsefalse$C_0001483096_20130302_20130402http://www.sec.gov/CIK0001483096duration2013-03-02T00:00:002013-04-02T00:00:00U_pureStandardhttp://www.xbrl.org/2003/instancepure0U_iso4217USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170U_iso4217USD_sharesDividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instanceshares0USDUSD$2false USDfalsefalse$C_0001483096_20121201_20121218http://www.sec.gov/CIK0001483096duration2012-12-01T00:00:002012-12-18T00:00:00U_iso4217USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170U_iso4217USD_sharesDividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instanceshares0USDUSD$3false USDfalsefalse$C_0001483096_20121201_20121220http://www.sec.gov/CIK0001483096duration2012-12-01T00:00:002012-12-20T00:00:00U_pureStandardhttp://www.xbrl.org/2003/instancepure0U_iso4217USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$4false falsefalseC_0001483096_20130101_20130630http://www.sec.gov/CIK0001483096duration2013-01-01T00:00:002013-06-30T00:00:00U_pureStandardhttp://www.xbrl.org/2003/instancepure01true 3acmp_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureLineItemsacmp_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]2false 4us-gaap_LimitedLiabilityCompanyLLCOrLimitedPartnershipLPManagingMemberOrGeneralPartnerOwnershipInterestus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truetruefalse0.0200.020falsefalsefalse2falsefalsefalse00falsefalsefalse3truetruefalse0.0200.020falsefalsefalse4truetruefalse0.5000.500falsefalsefalsenum:percentItemTypepureThe number of units or percentage investment held by the managing member or general partner of the LLC or LP.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 15 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055 false0General partnership interest3false 4us-gaap_CommonStockParOrStatedValuePerShareus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse39.8639.86USD$falsetruefalse2truefalsefalse32.1532.15USD$falsetruefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsenum:perShareItemTypedecimalFace amount or stated value of common stock per share; generally not indicative of the fair market value per share.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 129 -Paragraph 4 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.29) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 30 -Article 5 false3Common stock, par value4false 4us-gaap_ProceedsFromIssuanceInitialPublicOfferingus-gaap_truedebitdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse400100000400100000USD$falsetruefalse2truefalsefalse569300000569300000USD$falsetruefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryThe cash inflow associated with the amount received from entity's first offering of stock to the public.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Financing Activities -URI http://asc.fasb.org/extlink&oid=6513228 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3255-108585 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 19 -Subparagraph a -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false2Gross offering proceeds5false 4us-gaap_GeneralPartnersContributedCapitalus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse84000008400000USD$falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryThe amount of capital contributed by the general partner.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 5 -Subparagraph (SAB TOPIC 4.F) -URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187171-122770 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055 false2Capital contribution from Partnerships' general partner6false 4us-gaap_PartnersCapitalAccountSaleOfUnitsus-gaap_truecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse712100000712100000USD$falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryTotal change in each class of partners' capital accounts during the year due to the sale of units. All partners include general, limited and preferred partners.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187171-122770 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 15 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false2Partners' capital account, sale of units7false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5false truefalseC_0001483096_us-gaapStatementClassOfStockAxis_acmpSubordinatedUnitsMember_20130630http://www.sec.gov/CIK0001483096instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseSubordinated Unitsus-gaap_StatementClassOfStockAxisxbrldihttp://xbrl.org/2006/xbrldiacmp_SubordinatedUnitsMemberus-gaap_StatementClassOfStockAxisexplicitMemberU_sharesStandardhttp://www.xbrl.org/2003/instanceshares0nanafalse0Subordinated Units8true 3acmp_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureLineItemsacmp_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]9false 4us-gaap_LimitedPartnersCapitalAccountUnitsOutstandingus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truefalsefalse3453806134538061falsefalsefalsexbrli:sharesItemTypesharesThe number of limited partner units outstanding.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 5 -Subparagraph (SAB TOPIC 4.F) -URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187171-122770 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section F Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 10 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false1Partnership units outstanding10false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse6false truefalseC_0001483096_us-gaapStatementClassOfStockAxis_us-gaapGeneralPartnerMember_20130101_20130630http://www.sec.gov/CIK0001483096duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseGeneral Partnerus-gaap_StatementClassOfStockAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_GeneralPartnerMemberus-gaap_StatementClassOfStockAxisexplicitMemberU_pureStandardhttp://www.xbrl.org/2003/instancepure0U_sharesStandardhttp://www.xbrl.org/2003/instanceshares0nanafalse0General Partner11true 3acmp_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureLineItemsacmp_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]12false 4us-gaap_LimitedPartnersCapitalAccountUnitsOutstandingus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truefalsefalse20424582042458falsefalsefalsexbrli:sharesItemTypesharesThe number of limited partner units outstanding.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 5 -Subparagraph (SAB TOPIC 4.F) -URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187171-122770 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section F Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 10 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false1Partnership units outstanding13false 4us-gaap_LimitedLiabilityCompanyLLCOrLimitedPartnershipLPManagingMemberOrGeneralPartnerOwnershipInterestus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truetruefalse0.0100.010falsefalsefalsenum:percentItemTypepureThe number of units or percentage investment held by the managing member or general partner of the LLC or LP.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 15 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055 false0General partnership interest14false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse7false truefalseC_0001483096_us-gaapStatementClassOfStockAxis_acmpCommonUnitsMember_20130402http://www.sec.gov/CIK0001483096instant2013-04-02T00:00:000001-01-01T00:00:00falsefalseCommon Unitsus-gaap_StatementClassOfStockAxisxbrldihttp://xbrl.org/2006/xbrldiacmp_CommonUnitsMemberus-gaap_StatementClassOfStockAxisexplicitMemberU_sharesStandardhttp://www.xbrl.org/2003/instanceshares0nanafalse0Common Units15true 3acmp_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureLineItemsacmp_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]16false 4us-gaap_CommonStockSharesIssuedus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse1035000010350000falsefalsefalse2truefalsefalse1840000018400000falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:sharesItemTypesharesTotal number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.29) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 30 -Article 5 false1Common stock, shares issued17false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse9false truefalseC_0001483096_us-gaapStatementClassOfStockAxis_acmpUnderwritersOverallotmentOptionMember_20130402http://www.sec.gov/CIK0001483096instant2013-04-02T00:00:000001-01-01T00:00:00falsefalseUnderwriters Overallotment Optionus-gaap_StatementClassOfStockAxisxbrldihttp://xbrl.org/2006/xbrldiacmp_UnderwritersOverallotmentOptionMemberus-gaap_StatementClassOfStockAxisexplicitMemberU_sharesStandardhttp://www.xbrl.org/2003/instanceshares0nanafalse0Underwriters Overallotment Option18true 3acmp_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureLineItemsacmp_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]19false 4us-gaap_CommonStockSharesIssuedus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse13500001350000falsefalsefalse2truefalsefalse24000002400000falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:sharesItemTypesharesTotal number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.29) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 30 -Article 5 false1Common stock, shares issued20false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse11false truefalseC_0001483096_us-gaapStatementClassOfStockAxis_acmpClassBUnitsMember_20121201_20121220http://www.sec.gov/CIK0001483096duration2012-12-01T00:00:002012-12-20T00:00:00falsefalseConvertible Class B Unitsus-gaap_StatementClassOfStockAxisxbrldihttp://xbrl.org/2006/xbrldiacmp_ClassBUnitsMemberus-gaap_StatementClassOfStockAxisexplicitMemberU_sharesStandardhttp://www.xbrl.org/2003/instanceshares0nanafalse0Convertible Class B Units21true 3acmp_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureLineItemsacmp_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]22false 4us-gaap_LimitedPartnersCapitalAccountUnitsOutstandingus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truefalsefalse60803656080365falsefalsefalsexbrli:sharesItemTypesharesThe number of limited partner units outstanding.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 5 -Subparagraph (SAB TOPIC 4.F) -URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187171-122770 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section F Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 10 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false1Partnership units outstanding23false 4us-gaap_PartnersCapitalAccountUnitsSaleOfUnitsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse59000005900000falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:sharesItemTypesharesTotal units issued during the year due to the sale of units. All partners include general, limited and preferred partners.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187085-122770 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 15 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055 false1Partners' capital account units, sale of units24false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse13false truefalseC_0001483096_us-gaapStatementClassOfStockAxis_acmpClassCUnitsMember_20121201_20121220http://www.sec.gov/CIK0001483096duration2012-12-01T00:00:002012-12-20T00:00:00falsefalseSubordinated Class C Unitsus-gaap_StatementClassOfStockAxisxbrldihttp://xbrl.org/2006/xbrldiacmp_ClassCUnitsMemberus-gaap_StatementClassOfStockAxisexplicitMemberU_sharesStandardhttp://www.xbrl.org/2003/instanceshares0nanafalse0Subordinated Class C Units25true 3acmp_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureLineItemsacmp_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]26false 4us-gaap_LimitedPartnersCapitalAccountUnitsOutstandingus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truefalsefalse55996345599634falsefalsefalsexbrli:sharesItemTypesharesThe number of limited partner units outstanding.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 5 -Subparagraph (SAB TOPIC 4.F) -URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187171-122770 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section F Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 10 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false1Partnership units outstanding27false 4us-gaap_PartnersCapitalAccountUnitsSaleOfUnitsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse56000005600000falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:sharesItemTypesharesTotal units issued during the year due to the sale of units. All partners include general, limited and preferred partners.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187085-122770 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 15 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055 false1Partners' capital account units, sale of units28false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse15false USDtruefalse$C_0001483096_us-gaapBusinessAcquisitionAxis_acmpChesapeakeOperatingIncMember_20130630http://www.sec.gov/CIK0001483096instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseChesapeake Midstream Operating, L.L.C.us-gaap_BusinessAcquisitionAxisxbrldihttp://xbrl.org/2006/xbrldiacmp_ChesapeakeOperatingIncMemberus-gaap_BusinessAcquisitionAxisexplicitMemberU_pureStandardhttp://www.xbrl.org/2003/instancepure0U_iso4217USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Chesapeake Midstream Operating, L.L.C.29true 3acmp_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureLineItemsacmp_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]30false 4us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquiredus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truetruefalse1.001.00falsefalsefalsenum:percentItemTypepurePercentage of voting equity interests acquired in the business combination.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=7659399&loc=d3e1392-128463 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141R -Paragraph 68 -Subparagraph c -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false0Percentage of equity interest acquired31false 4us-gaap_BusinessAcquisitionCostOfAcquiredEntityPurchasePriceus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truefalsefalse21600000002160000000USD$falsefalsefalsexbrli:monetaryItemTypemonetaryThe total cost of the acquired entity including the cash paid to shareholders of acquired entities, fair value of debt and equity securities issued to shareholders of acquired entities, the fair value of the liabilities assumed, and direct costs of the acquisition.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 51 -Subparagraph d -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false2Consideration paid for acquisition32false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse16false truefalseC_0001483096_us-gaapBusinessAcquisitionAxis_acmpChesapeakeOperatingIncMember_us-gaapFiniteLivedIntangibleAssetsByMajorClassAxis_acmpGasGatheringAgreementMember_20130101_20130630http://www.sec.gov/CIK0001483096duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseChesapeake Midstream Operating, L.L.C.us-gaap_BusinessAcquisitionAxisxbrldihttp://xbrl.org/2006/xbrldiacmp_ChesapeakeOperatingIncMemberus-gaap_BusinessAcquisitionAxisexplicitMemberfalsefalseGas Gathering Agreementus-gaap_FiniteLivedIntangibleAssetsByMajorClassAxisxbrldihttp://xbrl.org/2006/xbrldiacmp_GasGatheringAgreementMemberus-gaap_FiniteLivedIntangibleAssetsByMajorClassAxisexplicitMemberU_acmpmiStandardhttp://www.accessmidstream.com/20130630miacmp0U_utracreStandardhttp://www.xbrl.org/2009/utracreutr0nanafalse0Chesapeake Midstream Operating, L.L.C. | Gas Gathering Agreement33true 3acmp_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureLineItemsacmp_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]34false 4acmp_AreaOfFacilityacmp_falsenainstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truefalsefalse43000004300000falsefalsefalsenum:areaItemTypedecimalArea Of FacilityNo definition available.false256Pipeline area covered35false 4acmp_LengthOfPipelineacmp_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truefalsefalse16751675falsefalsefalsexbrli:integerItemTypeintegerLength Of PipelineNo definition available.false256Pipeline36false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse17false truefalseC_0001483096_us-gaapBusinessAcquisitionAxis_acmpChesapeakeOperatingIncMember_us-gaapFiniteLivedIntangibleAssetsByMajorClassAxis_acmpGasGatheringAgreementMember_us-gaapRangeAxis_us-gaapMinimumMember_20130101_20130630http://www.sec.gov/CIK0001483096duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseChesapeake Midstream Operating, L.L.C.us-gaap_BusinessAcquisitionAxisxbrldihttp://xbrl.org/2006/xbrldiacmp_ChesapeakeOperatingIncMemberus-gaap_BusinessAcquisitionAxisexplicitMemberfalsefalseGas Gathering Agreementus-gaap_FiniteLivedIntangibleAssetsByMajorClassAxisxbrldihttp://xbrl.org/2006/xbrldiacmp_GasGatheringAgreementMemberus-gaap_FiniteLivedIntangibleAssetsByMajorClassAxisexplicitMemberfalsefalseMinimumus-gaap_RangeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_MinimumMemberus-gaap_RangeAxisexplicitMembernanafalse0Chesapeake Midstream Operating, L.L.C. | Gas Gathering Agreement | Minimum37true 3acmp_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureLineItemsacmp_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]38false 4acmp_OperatingAgreementTermacmp_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse0010 yearsfalsefalsefalsexbrli:durationItemTypenaOperating Agreement TermNo definition available.false0Term of agreements associated with assets39false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse18false truefalseC_0001483096_us-gaapBusinessAcquisitionAxis_acmpChesapeakeOperatingIncMember_us-gaapFiniteLivedIntangibleAssetsByMajorClassAxis_acmpGasGatheringAgreementMember_us-gaapRangeAxis_us-gaapMaximumMember_20130101_20130630http://www.sec.gov/CIK0001483096duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseChesapeake Midstream Operating, L.L.C.us-gaap_BusinessAcquisitionAxisxbrldihttp://xbrl.org/2006/xbrldiacmp_ChesapeakeOperatingIncMemberus-gaap_BusinessAcquisitionAxisexplicitMemberfalsefalseGas Gathering Agreementus-gaap_FiniteLivedIntangibleAssetsByMajorClassAxisxbrldihttp://xbrl.org/2006/xbrldiacmp_GasGatheringAgreementMemberus-gaap_FiniteLivedIntangibleAssetsByMajorClassAxisexplicitMemberfalsefalseMaximumus-gaap_RangeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_MaximumMemberus-gaap_RangeAxisexplicitMembernanafalse0Chesapeake Midstream Operating, L.L.C. | Gas Gathering Agreement | Maximum40true 3acmp_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureLineItemsacmp_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]41false 4acmp_OperatingAgreementTermacmp_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse0020 yearsfalsefalsefalsexbrli:durationItemTypenaOperating Agreement TermNo definition available.false0Term of agreements associated with assets42false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse19false truefalseC_0001483096_us-gaapBusinessAcquisitionAxis_acmpBusinessAcquisitionTwoMember_20130101_20130630http://www.sec.gov/CIK0001483096duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseWilliams Acquisitionus-gaap_BusinessAcquisitionAxisxbrldihttp://xbrl.org/2006/xbrldiacmp_BusinessAcquisitionTwoMemberus-gaap_BusinessAcquisitionAxisexplicitMemberU_pureStandardhttp://www.xbrl.org/2003/instancepure0nanafalse0Williams Acquisition43true 3acmp_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureLineItemsacmp_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]44false 4us-gaap_LimitedLiabilityCompanyLLCOrLimitedPartnershipLPManagingMemberOrGeneralPartnerOwnershipInterestus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truetruefalse0.50.5falsefalsefalsenum:percentItemTypepureThe number of units or percentage investment held by the managing member or general partner of the LLC or LP.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 15 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055 false0General partnership interest45false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse20false truefalseC_0001483096_us-gaapBusinessAcquisitionAxis_acmpBusinessAcquisitionTwoMember_us-gaapStatementClassOfStockAxis_acmpSubordinatedUnitsMember_20130630http://www.sec.gov/CIK0001483096instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseWilliams Acquisitionus-gaap_BusinessAcquisitionAxisxbrldihttp://xbrl.org/2006/xbrldiacmp_BusinessAcquisitionTwoMemberus-gaap_BusinessAcquisitionAxisexplicitMemberfalsefalseSubordinated Unitsus-gaap_StatementClassOfStockAxisxbrldihttp://xbrl.org/2006/xbrldiacmp_SubordinatedUnitsMemberus-gaap_StatementClassOfStockAxisexplicitMemberU_sharesStandardhttp://www.xbrl.org/2003/instanceshares0nanafalse0Williams Acquisition | Subordinated Units46true 3acmp_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureLineItemsacmp_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]47false 4us-gaap_LimitedPartnersCapitalAccountUnitsOutstandingus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truefalsefalse3453806134538061falsefalsefalsexbrli:sharesItemTypesharesThe number of limited partner units outstanding.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 5 -Subparagraph (SAB TOPIC 4.F) -URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187171-122770 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section F Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 10 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false1Partnership units outstanding48false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse21false USDtruefalse$C_0001483096_us-gaapBusinessAcquisitionAxis_acmpBusinessAcquisitionTwoMember_us-gaapStatementClassOfStockAxis_us-gaapGeneralPartnerMember_20130630http://www.sec.gov/CIK0001483096instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseWilliams Acquisitionus-gaap_BusinessAcquisitionAxisxbrldihttp://xbrl.org/2006/xbrldiacmp_BusinessAcquisitionTwoMemberus-gaap_BusinessAcquisitionAxisexplicitMemberfalsefalseGeneral Partnerus-gaap_StatementClassOfStockAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_GeneralPartnerMemberus-gaap_StatementClassOfStockAxisexplicitMemberU_iso4217USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Williams Acquisition | General Partner49true 3acmp_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureLineItemsacmp_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]50false 4us-gaap_BusinessAcquisitionCostOfAcquiredEntityPurchasePriceus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truefalsefalse18000000001800000000USD$falsetruefalsexbrli:monetaryItemTypemonetaryThe total cost of the acquired entity including the cash paid to shareholders of acquired entities, fair value of debt and equity securities issued to shareholders of acquired entities, the fair value of the liabilities assumed, and direct costs of the acquisition.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 51 -Subparagraph d -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false2Consideration paid for acquisition51false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse22false truefalseC_0001483096_us-gaapBusinessAcquisitionAxis_acmpGipMember_20130101_20130630http://www.sec.gov/CIK0001483096duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseGIP I Entities and GIP IIus-gaap_BusinessAcquisitionAxisxbrldihttp://xbrl.org/2006/xbrldiacmp_GipMemberus-gaap_BusinessAcquisitionAxisexplicitMemberU_pureStandardhttp://www.xbrl.org/2003/instancepure0U_sharesStandardhttp://www.xbrl.org/2003/instanceshares0nanafalse0GIP I Entities and GIP II52true 3acmp_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureLineItemsacmp_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]53false 4us-gaap_LimitedPartnersCapitalAccountUnitsOutstandingus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truefalsefalse20424582042458falsefalsefalsexbrli:sharesItemTypesharesThe number of limited partner units outstanding.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 5 -Subparagraph (SAB TOPIC 4.F) -URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187171-122770 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section F Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 10 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false1Partnership units outstanding54false 4us-gaap_LimitedLiabilityCompanyLLCOrLimitedPartnershipLPManagingMemberOrGeneralPartnerOwnershipInterestus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truetruefalse0.5000.500falsefalsefalsenum:percentItemTypepureThe number of units or percentage investment held by the managing member or general partner of the LLC or LP.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 15 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055 false0General partnership interest55false 4us-gaap_LimitedLiabilityCompanyLLCOrLimitedPartnershipLPMembersOrLimitedPartnersOwnershipInterestus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truetruefalse0.3910.391falsefalsefalsenum:percentItemTypepureThe number of units or percentage investment held by one or more members or limited partners of the LLC or LP.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055 false0Limited partnership interest56false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse23false truefalseC_0001483096_us-gaapBusinessAcquisitionAxis_acmpGipMember_us-gaapStatementClassOfStockAxis_acmpSubordinatedUnitsMember_20130630http://www.sec.gov/CIK0001483096instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseGIP I Entities and GIP IIus-gaap_BusinessAcquisitionAxisxbrldihttp://xbrl.org/2006/xbrldiacmp_GipMemberus-gaap_BusinessAcquisitionAxisexplicitMemberfalsefalseSubordinated Unitsus-gaap_StatementClassOfStockAxisxbrldihttp://xbrl.org/2006/xbrldiacmp_SubordinatedUnitsMemberus-gaap_StatementClassOfStockAxisexplicitMemberU_sharesStandardhttp://www.xbrl.org/2003/instanceshares0nanafalse0GIP I Entities and GIP II | Subordinated Units57true 3acmp_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureLineItemsacmp_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]58false 4us-gaap_LimitedPartnersCapitalAccountUnitsOutstandingus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truefalsefalse3453806134538061falsefalsefalsexbrli:sharesItemTypesharesThe number of limited partner units outstanding.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 5 -Subparagraph (SAB TOPIC 4.F) -URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187171-122770 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section F Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 10 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false1Partnership units outstanding59false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse24false truefalseC_0001483096_us-gaapBusinessAcquisitionAxis_acmpGipMember_us-gaapStatementClassOfStockAxis_us-gaapGeneralPartnerMember_20130101_20130630http://www.sec.gov/CIK0001483096duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseGIP I Entities and GIP IIus-gaap_BusinessAcquisitionAxisxbrldihttp://xbrl.org/2006/xbrldiacmp_GipMemberus-gaap_BusinessAcquisitionAxisexplicitMemberfalsefalseGeneral Partnerus-gaap_StatementClassOfStockAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_GeneralPartnerMemberus-gaap_StatementClassOfStockAxisexplicitMemberU_pureStandardhttp://www.xbrl.org/2003/instancepure0nanafalse0GIP I Entities and GIP II | General Partner60true 3acmp_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureLineItemsacmp_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]61false 4us-gaap_LimitedLiabilityCompanyLLCOrLimitedPartnershipLPManagingMemberOrGeneralPartnerOwnershipInterestus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truetruefalse0.0100.010falsefalsefalsenum:percentItemTypepureThe number of units or percentage investment held by the managing member or general partner of the LLC or LP.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 15 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055 false0General partnership interest62false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse25false truefalseC_0001483096_us-gaapBusinessAcquisitionAxis_acmpGipMember_us-gaapStatementClassOfStockAxis_acmpCommonUnitsMember_20130630http://www.sec.gov/CIK0001483096instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseGIP I Entities and GIP IIus-gaap_BusinessAcquisitionAxisxbrldihttp://xbrl.org/2006/xbrldiacmp_GipMemberus-gaap_BusinessAcquisitionAxisexplicitMemberfalsefalseCommon Unitsus-gaap_StatementClassOfStockAxisxbrldihttp://xbrl.org/2006/xbrldiacmp_CommonUnitsMemberus-gaap_StatementClassOfStockAxisexplicitMemberU_sharesStandardhttp://www.xbrl.org/2003/instanceshares0nanafalse0GIP I Entities and GIP II | Common Units63true 3acmp_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureLineItemsacmp_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]64false 4us-gaap_LimitedPartnersCapitalAccountUnitsOutstandingus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truefalsefalse3370466633704666falsefalsefalsexbrli:sharesItemTypesharesThe number of limited partner units outstanding.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 5 -Subparagraph (SAB TOPIC 4.F) -URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187171-122770 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section F Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 10 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false1Partnership units outstanding65false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse26false truefalseC_0001483096_us-gaapBusinessAcquisitionAxis_acmpGipMember_us-gaapStatementClassOfStockAxis_acmpClassBUnitsMember_20130630http://www.sec.gov/CIK0001483096instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseGIP I Entities and GIP IIus-gaap_BusinessAcquisitionAxisxbrldihttp://xbrl.org/2006/xbrldiacmp_GipMemberus-gaap_BusinessAcquisitionAxisexplicitMemberfalsefalseConvertible Class B Unitsus-gaap_StatementClassOfStockAxisxbrldihttp://xbrl.org/2006/xbrldiacmp_ClassBUnitsMemberus-gaap_StatementClassOfStockAxisexplicitMemberU_sharesStandardhttp://www.xbrl.org/2003/instanceshares0nanafalse0GIP I Entities and GIP II | Convertible Class B Units66true 3acmp_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureLineItemsacmp_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]67false 4us-gaap_LimitedPartnersCapitalAccountUnitsOutstandingus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truefalsefalse60803656080365falsefalsefalsexbrli:sharesItemTypesharesThe number of limited partner units outstanding.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 5 -Subparagraph (SAB TOPIC 4.F) -URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187171-122770 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section F Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 10 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false1Partnership units outstanding68false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse27false truefalseC_0001483096_us-gaapBusinessAcquisitionAxis_acmpGipMember_us-gaapStatementClassOfStockAxis_acmpClassCUnitsMember_20130630http://www.sec.gov/CIK0001483096instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseGIP I Entities and GIP IIus-gaap_BusinessAcquisitionAxisxbrldihttp://xbrl.org/2006/xbrldiacmp_GipMemberus-gaap_BusinessAcquisitionAxisexplicitMemberfalsefalseSubordinated Class C Unitsus-gaap_StatementClassOfStockAxisxbrldihttp://xbrl.org/2006/xbrldiacmp_ClassCUnitsMemberus-gaap_StatementClassOfStockAxisexplicitMemberU_sharesStandardhttp://www.xbrl.org/2003/instanceshares0nanafalse0GIP I Entities and GIP II | Subordinated Class C Units69true 3acmp_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureLineItemsacmp_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]70false 4us-gaap_LimitedPartnersCapitalAccountUnitsOutstandingus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truefalsefalse55996345599634falsefalsefalsexbrli:sharesItemTypesharesThe number of limited partner units outstanding.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 5 -Subparagraph (SAB TOPIC 4.F) -URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187171-122770 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section F Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 10 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false1Partnership units outstanding71false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse28false truefalseC_0001483096_us-gaapBusinessAcquisitionAxis_acmpAggregateMember_20130101_20130630http://www.sec.gov/CIK0001483096duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseAggregateus-gaap_BusinessAcquisitionAxisxbrldihttp://xbrl.org/2006/xbrldiacmp_AggregateMemberus-gaap_BusinessAcquisitionAxisexplicitMemberU_pureStandardhttp://www.xbrl.org/2003/instancepure0nanafalse0Aggregate72true 3acmp_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureLineItemsacmp_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]73false 4us-gaap_LimitedLiabilityCompanyLLCOrLimitedPartnershipLPMembersOrLimitedPartnersOwnershipInterestus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truetruefalse0.2260.226falsefalsefalsenum:percentItemTypepureThe number of units or percentage investment held by one or more members or limited partners of the LLC or LP.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055 false0Limited partnership interest74false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse29false truefalseC_0001483096_us-gaapBusinessAcquisitionAxis_acmpPubliclyOwnedMember_20130101_20130630http://www.sec.gov/CIK0001483096duration2013-01-01T00:00:002013-06-30T00:00:00falsefalsePublicly Ownedus-gaap_BusinessAcquisitionAxisxbrldihttp://xbrl.org/2006/xbrldiacmp_PubliclyOwnedMemberus-gaap_BusinessAcquisitionAxisexplicitMemberU_pureStandardhttp://www.xbrl.org/2003/instancepure0nanafalse0Publicly Owned75true 3acmp_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureLineItemsacmp_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]76false 4us-gaap_LimitedLiabilityCompanyLLCOrLimitedPartnershipLPMembersOrLimitedPartnersOwnershipInterestus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truetruefalse0.3630.363falsefalsefalsenum:percentItemTypepureThe number of units or percentage investment held by one or more members or limited partners of the LLC or LP.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055 false0Limited partnership interest77false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse30false truefalseC_0001483096_us-gaapBusinessAcquisitionAxis_acmpPubliclyOwnedMember_us-gaapStatementClassOfStockAxis_acmpCommonUnitsMember_20130630http://www.sec.gov/CIK0001483096instant2013-06-30T00:00:000001-01-01T00:00:00falsefalsePublicly Ownedus-gaap_BusinessAcquisitionAxisxbrldihttp://xbrl.org/2006/xbrldiacmp_PubliclyOwnedMemberus-gaap_BusinessAcquisitionAxisexplicitMemberfalsefalseCommon Unitsus-gaap_StatementClassOfStockAxisxbrldihttp://xbrl.org/2006/xbrldiacmp_CommonUnitsMemberus-gaap_StatementClassOfStockAxisexplicitMemberU_sharesStandardhttp://www.xbrl.org/2003/instanceshares0nanafalse0Publicly Owned | Common Units78true 3acmp_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureLineItemsacmp_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]79false 4us-gaap_LimitedPartnersCapitalAccountUnitsOutstandingus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truefalsefalse7402011574020115falsefalsefalsexbrli:sharesItemTypesharesThe number of limited partner units outstanding.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 5 -Subparagraph (SAB TOPIC 4.F) -URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187171-122770 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section F Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 10 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false1Partnership units outstandingfalseDescription of Business and Basis of Presentation - Additional Information (Detail) (USD $)NoRoundingNoRoundingNoRoundingUnKnowntruefalsefalseSheethttp://www.accessmidstream.com/20130630/taxonomy/role/DisclosureDescriptionOfBusinessAndBasisOfPresentationAdditionalInformationDetail479