Derivative Instruments, Hedging Activities and Fair Value Measurements, Nonrecurring Fair Value Measurements (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2014	Mar. 31, 2013
Asset Impairment Charges [Abstract]
Non-cash asset impairment charges	$ 8.8	$ 11.0
Impairment of long-lived assets to be disposed of by sale	5.0
Impairment of long-lived assets disposed of other than by sale	3.8	11.0
NGL Pipelines and Services [Member]
Asset Impairment Charges [Abstract]
Non-cash asset impairment charges	2.6	1.0
Onshore Natural Gas Pipelines and Services [Member]
Asset Impairment Charges [Abstract]
Non-cash asset impairment charges	0.2	0
Onshore Crude Oil Pipelines and Services [Member]
Asset Impairment Charges [Abstract]
Non-cash asset impairment charges	1.0	0
Petrochemical and Refined Products Services [Member]
Asset Impairment Charges [Abstract]
Non-cash asset impairment charges	5.0	10.0
Fair Value, Measurements, Nonrecurring [Member] \| Long-lived Assets Disposed of Other Than By Sale [Member]
Assets, Fair Value Disclosure [Abstract]
Assets, fair value	0	0
Fair Value, Measurements, Nonrecurring [Member] \| Long-lived Assets Disposed of By Sale [Member]
Assets, Fair Value Disclosure [Abstract]
Assets, fair value	0.1
Fair Value, Measurements, Nonrecurring [Member] \| Level 1 [Member] \| Long-lived Assets Disposed of Other Than By Sale [Member]
Assets, Fair Value Disclosure [Abstract]
Assets, fair value	0
Fair Value, Measurements, Nonrecurring [Member] \| Level 1 [Member] \| Long-lived Assets Disposed of By Sale [Member]
Assets, Fair Value Disclosure [Abstract]
Assets, fair value	0
Fair Value, Measurements, Nonrecurring [Member] \| Level 2 [Member] \| Long-lived Assets Disposed of Other Than By Sale [Member]
Assets, Fair Value Disclosure [Abstract]
Assets, fair value	0
Fair Value, Measurements, Nonrecurring [Member] \| Level 2 [Member] \| Long-lived Assets Disposed of By Sale [Member]
Assets, Fair Value Disclosure [Abstract]
Assets, fair value	0
Fair Value, Measurements, Nonrecurring [Member] \| Level 3 [Member] \| Long-lived Assets Disposed of Other Than By Sale [Member]
Assets, Fair Value Disclosure [Abstract]
Assets, fair value	0
Fair Value, Measurements, Nonrecurring [Member] \| Level 3 [Member] \| Long-lived Assets Disposed of By Sale [Member]
Assets, Fair Value Disclosure [Abstract]
Assets, fair value	$ 0.1

Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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-Section 50

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- Definition

The aggregate amount of write-downs for impairments recognized during the period for long-lived assets held for abandonment, exchange or sale.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

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The charge against earnings resulting from the write down of long lived assets other than goodwill due to the difference between the carrying value and lower fair value.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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