Average premium on long term debt outstanding.

No definition available.

Name:	acmp_AveragePremiumOnLongTermDebtOutstanding
Namespace Prefix:	acmp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

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 210.5-02.22(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Carrying amount of long-term debt, net of unamortized discount or premium, excluding amounts to be repaid within one year or the normal operating cycle, if longer (current maturities). Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

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 210.5-02.22)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_LongTermDebtNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Weighted average interest rate of long-term debt outstanding.

+ References

No definition available.

+ Details

Name:	us-gaap_LongtermDebtWeightedAverageInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Partnership's Average Interest Rate and Average Debt Balance (Detail) (USD $) In Thousands, unless otherwise specified					3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Dec. 31, 2013 Revolving Credit Facility	Mar. 31, 2014 Revolving Credit Facility Weighted Average	Mar. 31, 2014 5.875 Percent Senior Notes due April 2021	Dec. 31, 2013 5.875 Percent Senior Notes due April 2021	Aug. 14, 2013 5.875 Percent Senior Notes due April 2021	Apr. 19, 2011 5.875 Percent Senior Notes due April 2021	Mar. 31, 2014 5.875 Percent Senior Notes due April 2021 Weighted Average	Mar. 31, 2014 6.125 Percent Senior Notes due July 2022	Dec. 31, 2013 6.125 Percent Senior Notes due July 2022	Jan. 11, 2012 6.125 Percent Senior Notes due July 2022	Mar. 31, 2014 6.125 Percent Senior Notes due July 2022 Weighted Average	Mar. 31, 2014 4.875 Percent Senior Notes due May 2023	Dec. 31, 2013 4.875 Percent Senior Notes due May 2023	Dec. 19, 2012 4.875 Percent Senior Notes due May 2023	Mar. 31, 2014 4.875 Percent Senior Notes due May 2023 Weighted Average	Mar. 31, 2014 4.875 Percent Senior Notes due March 2024	Mar. 07, 2014 4.875 Percent Senior Notes due March 2024	Dec. 31, 2013 4.875 Percent Senior Notes due March 2024	Mar. 31, 2014 4.875 Percent Senior Notes due March 2024 Weighted Average
Debt Instrument [Line Items]
Average Interest Rate				2.187%	5.875%	5.875%	5.875%	5.875%	5.875%	6.125%	6.125%	6.125%	6.125%	4.875%	4.875%	4.875%	4.875%	4.875%	4.875%	4.875%	4.875%
Average Balance	$ 3,655,565	$ 3,249,230	$ 343,500	$ 322,167	$ 750,000	$ 750,000			$ 750,000	$ 750,000	$ 750,000		$ 750,000	$ 1,400,000	$ 1,400,000		$ 1,400,000	$ 750,000			$ 750,000
Premium on long-term debt, Average Interest Rate					5.875%
Premium on long-term debt, Average Balance					$ 5,648