Business Segments, Segment Reporting Information (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Information by business segment [Abstract]
Gross operating margin		$ 8,188.1	$ 8,289.8	$ 7,291.0
Revenues from third parties		27,163.0	32,721.9	36,426.5
Revenues from related parties		36.7	67.3	107.7
Intersegment and intrasegment revenues		0.0	0.0	0.0
Total revenues		27,199.7	32,789.2	36,534.2
Equity in income (loss) of unconsolidated affiliates		426.1	563.0	480.0
Property, plant and equipment, net		41,912.8	41,603.4	38,737.6
Investments in unconsolidated affiliates		2,429.2	2,600.2	2,615.1
Intangible assets, net		3,309.1	3,449.0	3,608.4
Goodwill		5,448.9	5,745.2	5,745.2
Segment assets		53,100.0	53,397.8	50,706.3
NGL Pipelines and Services [Member]
Information by business segment [Abstract]
Total revenues		11,177.2	13,470.7	15,648.9
Equity in income (loss) of unconsolidated affiliates		121.3	114.5	117.0
Intangible assets, net		334.1	360.2
Goodwill		2,651.7	2,651.7	2,651.7
Crude Oil Pipelines & Services [Member]
Information by business segment [Abstract]
Total revenues		6,689.0	10,287.3	11,042.6
Equity in income (loss) of unconsolidated affiliates		301.2	449.2	365.4
Intangible assets, net		1,936.6	2,001.9
Goodwill		1,841.0	1,841.0	1,841.0
Natural Gas Pipelines & Services [Member]
Information by business segment [Abstract]
Total revenues		2,553.1	3,169.4	3,454.4
Equity in income (loss) of unconsolidated affiliates		5.8	6.3	6.8
Intangible assets, net		905.0	941.2
Goodwill		0.0	296.3	296.3
Petrochemical & Refined Products Services [Member]
Information by business segment [Abstract]
Total revenues		6,780.4	5,861.8	6,388.3
Equity in income (loss) of unconsolidated affiliates	[1]	(2.2)	(7.0)	(9.2)
Intangible assets, net		133.4	145.7
Goodwill		956.2	956.2	956.2
Reportable Business Segments [Member] | NGL Pipelines and Services [Member]
Information by business segment [Abstract]
Gross operating margin		4,182.4	4,069.8	3,830.7
Revenues from third parties		11,170.6	13,460.8	15,630.5
Revenues from related parties		6.6	9.9	18.4
Intersegment and intrasegment revenues		29,010.3	20,840.4	26,453.6
Total revenues		40,187.5	34,311.1	42,102.5
Equity in income (loss) of unconsolidated affiliates		121.3	114.5	117.0
Property, plant and equipment, net		17,128.3	16,652.1	14,845.4
Investments in unconsolidated affiliates		671.6	703.8	662.0
Intangible assets, net		334.1	360.2	380.1
Goodwill		2,651.7	2,651.7	2,651.7
Segment assets		20,785.7	20,367.8	18,539.2
Reportable Business Segments [Member] | Crude Oil Pipelines & Services [Member]
Information by business segment [Abstract]
Gross operating margin		1,997.3	2,087.8	1,511.3
Revenues from third parties		6,668.8	10,244.6	10,968.2
Revenues from related parties		20.2	42.7	74.4
Intersegment and intrasegment revenues		24,531.3	34,613.0	35,490.4
Total revenues		31,220.3	44,900.3	46,533.0
Equity in income (loss) of unconsolidated affiliates		301.2	449.2	365.4
Property, plant and equipment, net		6,982.6	6,324.4	5,847.7
Investments in unconsolidated affiliates		1,723.7	1,866.5	1,867.5
Intangible assets, net		1,936.6	2,001.9	2,094.6
Goodwill		1,841.0	1,841.0	1,841.0
Segment assets		12,483.9	12,033.8	11,650.8
Reportable Business Segments [Member] | Natural Gas Pipelines & Services [Member]
Information by business segment [Abstract]
Gross operating margin		926.6	1,062.6	891.2
Revenues from third parties		2,543.2	3,154.7	3,439.5
Revenues from related parties		9.9	14.7	14.9
Intersegment and intrasegment revenues		460.1	624.7	721.9
Total revenues		3,013.2	3,794.1	4,176.3
Equity in income (loss) of unconsolidated affiliates		5.8	6.3	6.8
Property, plant and equipment, net		8,465.8	8,432.5	8,303.8
Investments in unconsolidated affiliates		31.4	27.3	22.8
Intangible assets, net		905.0	941.2	979.3
Goodwill		0.0	296.3	296.3
Segment assets		9,402.2	9,697.3	9,602.2
Reportable Business Segments [Member] | Petrochemical & Refined Products Services [Member]
Information by business segment [Abstract]
Gross operating margin		1,081.8	1,069.6	1,057.8
Revenues from third parties		6,780.4	5,861.8	6,388.3
Revenues from related parties		0.0	0.0	0.0
Intersegment and intrasegment revenues		5,379.4	2,481.3	2,917.5
Total revenues		12,159.8	8,343.1	9,305.8
Equity in income (loss) of unconsolidated affiliates		(2.2)	(7.0)	(9.2)
Property, plant and equipment, net		7,528.4	7,553.2	6,213.9
Investments in unconsolidated affiliates		2.5	2.6	62.8
Intangible assets, net		133.4	145.7	154.4
Goodwill		956.2	956.2	956.2
Segment assets		8,620.5	8,657.7	7,387.3
Eliminations [Member]
Information by business segment [Abstract]
Revenues from third parties		0.0	0.0	0.0
Revenues from related parties		0.0	0.0	0.0
Intersegment and intrasegment revenues		(59,381.1)	(58,559.4)	(65,583.4)
Total revenues		(59,381.1)	(58,559.4)	(65,583.4)
Equity in income (loss) of unconsolidated affiliates		0.0	0.0	0.0
Adjustments [Member]
Information by business segment [Abstract]
Property, plant and equipment, net		1,807.7	2,641.2	3,526.8
Investments in unconsolidated affiliates		0.0	0.0	0.0
Intangible assets, net		0.0	0.0	0.0
Goodwill		0.0	0.0	0.0
Segment assets		$ 1,807.7	$ 2,641.2	$ 3,526.8

[1] The losses recorded for this segment are primarily due to protection, maintenance and pipeline integrity costs of the idled Centennial Pipeline, which was purged and filled with nitrogen in 2013.