Business Segments, Consolidated Revenues and Expenses (Details) - USD ($) $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Consolidated Revenues [Abstract]
Total consolidated revenues		$ 6,478.8	$ 5,920.4	$ 5,617.8	$ 5,005.3	$ 6,155.0	$ 6,307.9	$ 7,092.5	$ 7,472.5	$ 23,022.3	$ 27,027.9	$ 47,951.2
Operating costs and expenses:
Cost of sales	[1]									15,710.9	19,612.9	40,464.1
Other operating costs and expenses	[2]									2,425.6	2,449.4	2,541.8
Depreciation, amortization and accretion										1,456.7	1,428.2	1,282.7
Asset impairment and related charges	[3]									52.8	162.6	34.0
Net losses (gains) attributable to asset sales and insurance recoveries										(2.5)	15.6	(102.1)
General and administrative costs										160.1	192.6	214.5
Total costs and expenses										19,803.6	$ 23,861.3	$ 44,435.0
Vitol Holding B.V. [Member]
Consolidated Revenues [Abstract]
Total consolidated revenues										$ 2,280.1
Vitol Holding B.V. [Member] | Revenues [Member]
Consolidated Revenues [Abstract]
Largest non-affiliated customer percentage										9.90%
Shell Oil Company [Member] | Revenues [Member]
Consolidated Revenues [Abstract]
Largest non-affiliated customer percentage											7.40%	8.50%
NGL Pipelines and Services [Member]
Consolidated Revenues [Abstract]
Sales of NGLs and related products										$ 8,380.5	$ 8,044.8	$ 15,460.1
Midstream services										1,862.0	1,743.2	1,629.7
Total consolidated revenues										10,242.5	9,788.0	17,089.8
NGL Pipelines and Services [Member] | Vitol Holding B.V. [Member]
Consolidated Revenues [Abstract]
Total consolidated revenues										1,830.1
Crude Oil Pipelines & Services [Member]
Consolidated Revenues [Abstract]
Sales of crude oil										5,802.5	9,732.9	19,783.9
Midstream services										712.5	573.0	400.4
Total consolidated revenues										6,515.0	10,305.9	20,184.3
Crude Oil Pipelines & Services [Member] | Vitol Holding B.V. [Member]
Consolidated Revenues [Abstract]
Total consolidated revenues										171.9
Natural Gas Pipelines & Services [Member]
Consolidated Revenues [Abstract]
Sales of natural gas										1,591.9	1,722.6	3,181.7
Midstream services										951.1	1,020.7	1,022.1
Total consolidated revenues										2,543.0	2,743.3	4,203.8
Natural Gas Pipelines & Services [Member] | Vitol Holding B.V. [Member]
Consolidated Revenues [Abstract]
Total consolidated revenues										7.8
Petrochemical and Refined Products Services [Member]
Consolidated Revenues [Abstract]
Sales of petrochemicals and refined products										2,921.9	3,333.5	5,575.5
Midstream services										799.9	778.4	741.0
Total consolidated revenues										3,721.8	4,111.9	6,316.5
Petrochemical and Refined Products Services [Member] | Vitol Holding B.V. [Member]
Consolidated Revenues [Abstract]
Total consolidated revenues										270.3
Offshore Pipelines And Services [Member]
Consolidated Revenues [Abstract]
Sales of natural gas										0.0	0.0	0.3
Sales of crude oil										0.0	3.2	8.6
Midstream services										0.0	75.6	147.9
Total consolidated revenues										$ 0.0	$ 78.8	$ 156.8

[1] Cost of sales is a component of "Operating costs and expenses," as presented on our Statements of Consolidated Operations. Fluctuations in these amounts are primarily due to changes in energy commodity prices and sales volumes associated with our marketing activities.

[2] Represents the cost of operating our plants, pipelines and other fixed assets excluding: depreciation, amortization and accretion charges; asset impairment and related charges; and net losses (or gains) attributable to asset sales and insurance recoveries.

[3] The amount presented for 2016 includes $7.1 million recorded in connection with the fire at Pascagoula (see Note 5).