Property, Plant and Equipment (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012		Mar. 31, 2011		Dec. 31, 2011
Property, plant and equipment and accumulated depreciation [Abstract]
Property, plant and equipment, gross	$ 28,359.4				$ 27,429.6
Less accumulated depreciation	5,449.1				5,238.0
Property, plant and equipment , net	22,910.3				22,191.6
Summary of depreciation expense and capitalized interest [Abstract]
Depreciation expense	212.0	[1]	186.5	[1]
Capitalized interest	30.6	[2]	17.2	[2]
Asset Retirement Obligations [Roll Forward]
ARO liability balance, December 31, 2011	112.0
Liabilities incurred during period	0.8
Liabilities settled during period	(1.6)
Revisions in estimated cash flows	3.4
Accretion expense	1.4
ARO liability balance, March 31, 2012	116.0
Capitalized costs, asset retirement costs	37.2				37.7
Forecasted accretion expense [Abstract]
Forecast accretion expense - Remainder of 2012	4.0
Forecast accretion expense - 2013	5.6
Forecast accretion expense - 2014	6.0
Forecast accretion expense - 2015	5.8
Forecast accretion expense - 2016	6.1
Plants, pipelines and facilities [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Property, plant and equipment, gross	22,567.2	[3]			22,354.4	[3]
Plants, pipelines and facilities [Member] | Minimum [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Estimated useful life	3 years 0 months 0 days	[3],[4]
Plants, pipelines and facilities [Member] | Maximum [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Estimated useful life	45 years 0 months 0 days	[3],[4]
Underground and other storage facilities [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Property, plant and equipment, gross	1,416.0	[5]			1,388.6	[5]
Underground and other storage facilities [Member] | Minimum [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Estimated useful life	5 years 0 months 0 days	[5],[6]
Underground and other storage facilities [Member] | Maximum [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Estimated useful life	40 years 0 months 0 days	[5],[6]
Platforms and facilities [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Property, plant and equipment, gross	637.5	[7]			637.5	[7]
Platforms and facilities [Member] | Minimum [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Estimated useful life	20 years 0 months 0 days	[7]
Platforms and facilities [Member] | Maximum [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Estimated useful life	31 years 0 months 0 days	[7]
Transportation equipment [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Property, plant and equipment, gross	153.1	[8]			151.5	[8]
Transportation equipment [Member] | Minimum [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Estimated useful life	3 years 0 months 0 days	[8]
Transportation equipment [Member] | Maximum [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Estimated useful life	10 years 0 months 0 days	[8]
Marine vessels [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Property, plant and equipment, gross	633.5	[9]			615.9	[9]
Marine vessels [Member] | Minimum [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Estimated useful life	15 years 0 months 0 days	[9]
Marine vessels [Member] | Maximum [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Estimated useful life	30 years 0 months 0 days	[9]
Land [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Property, plant and equipment, gross	141.3				136.1
Construction in progress [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Property, plant and equipment, gross	$ 2,810.8				$ 2,145.6
Processing plants [Member] | Minimum [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Estimated useful life	20 years 0 months 0 days
Processing plants [Member] | Maximum [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Estimated useful life	35 years 0 months 0 days
Pipelines and related equipment [Member] | Minimum [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Estimated useful life	5 years 0 months 0 days
Pipelines and related equipment [Member] | Maximum [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Estimated useful life	45 years 0 months 0 days
Terminal facilities [Member] | Minimum [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Estimated useful life	10 years 0 months 0 days
Terminal facilities [Member] | Maximum [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Estimated useful life	35 years 0 months 0 days
Office furniture and equipment [Member] | Minimum [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Estimated useful life	3 years 0 months 0 days
Office furniture and equipment [Member] | Maximum [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Estimated useful life	20 years 0 months 0 days
Buildings [Member] | Minimum [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Estimated useful life	20 years 0 months 0 days
Buildings [Member] | Maximum [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Estimated useful life	40 years 0 months 0 days
Laboratory and shop equipment [Member] | Minimum [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Estimated useful life	5 years 0 months 0 days
Laboratory and shop equipment [Member] | Maximum [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Estimated useful life	35 years 0 months 0 days
Underground storage facilities [Member] | Minimum [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Estimated useful life	5 years 0 months 0 days
Underground storage facilities [Member] | Maximum [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Estimated useful life	35 years 0 months 0 days
Storage tanks [Member] | Minimum [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Estimated useful life	10 years 0 months 0 days
Storage tanks [Member] | Maximum [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Estimated useful life	40 years 0 months 0 days
Water wells [Member] | Minimum [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Estimated useful life	5 years 0 months 0 days
Water wells [Member] | Maximum [Member]
Property, plant and equipment and accumulated depreciation [Abstract]
Estimated useful life	35 years 0 months 0 days

[1] Depreciation expense is a component of "Costs and expenses" as presented in our Unaudited Condensed Statements of Consolidated Operations.

[2] Capitalized interest reduces interest expense during the period it is recorded and increases the carrying value of the associated asset, which will subsequently increase depreciation expense once the asset is placed in service.

[3] Plants and pipelines include processing plants; NGL, natural gas, crude oil and petrochemical and refined products pipelines; terminal loading and unloading facilities; office furniture and equipment; buildings; laboratory and shop equipment and related assets.

[4] In general, the estimated useful lives of major assets within this category are: processing plants, 20-35 years; pipelines and related equipment, 5-45 years; terminal facilities, 10-35 years; office furniture and equipment, 3-20 years; buildings, 20-40 years; and laboratory and shop equipment, 5-35 years.

[5] Underground and other storage facilities include underground product storage caverns; above ground storage tanks; water wells and related assets.

[6] In general, the estimated useful lives of assets within this category are: underground storage facilities, 5-35 years; storage tanks, 10-40 years; and water wells, 5-35 years.

[7] Platforms and facilities include offshore platforms and related facilities and other associated assets located in the Gulf of Mexico.

[8] Transportation equipment includes tractor-trailer tank trucks and other vehicles and similar assets used in our operations.

[9] Marine vessels include tow boats, barges and related equipment used in our marine transportation business.