Disposal Group, Equity Interest Sold

No definition available.

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Namespace Prefix:	kmi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, 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 350
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16265-109275

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Difference between amount at which an investment accounted for under the equity method of accounting is carried (reported) on the balance sheet and amount of underlying equity in net assets the reporting Entity has in the investee.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=66011266&loc=d3e33918-111571

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Details

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- Details

Name:	invest_InvestmentAxis=us-gaap_AcquisitionRelatedCostsMember
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- Details

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- Details

Name:	us-gaap_ValuationTechniqueAxis=kmi_AmortizedMember
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- Details

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Data Type:	na
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- Details

Name:	us-gaap_ValuationTechniqueAxis=kmi_UnamortizationMember
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Summary of Significant Accounting Policies Equity investment and excess costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Sep. 01, 2016
Schedule of Equity Method Investments [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	16 years
Sale Equity Interest in SNG [Member]
Schedule of Equity Method Investments [Line Items]
Disposal Group, Equity Interest Sold			50.00%
Acquisition-related Costs [Member]
Schedule of Equity Method Investments [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	14 years
Property, Plant and Equipment, Other Types [Member] \| Amortized [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method of Accounting and Excess Investment Cost	$ 732	$ 767
Goodwill [Member] \| Unamortization [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method of Accounting and Excess Investment Cost	$ 956	$ 956