Business Segments, Segment Reporting Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Information by business segment [Abstract]
Segment gross operating margin	$ 2,033.3	$ 2,051.4	$ 6,093.4	$ 6,266.0
Mark-to-market gains (losses) in gross operating margin	(37.7)	9.1	53.7	92.9
Mark-to-market loss in interest expense	0.0	(94.9)	0.0	(94.9)
Total mark-to-market gains (losses)	(37.7)	(85.8)	53.7	(2.0)
Revenues from third parties	6,914.5	7,948.5	20,126.3	24,730.2
Revenues from related parties	7.5	15.6	29.2	53.7
Intersegment and intrasegment revenues	0.0	0.0	0.0	0.0
Total revenues	6,922.0	7,964.1	20,155.5	24,783.9
Equity in income (loss) of unconsolidated affiliates	82.0	139.3	336.1	431.3
Property, plant and equipment, net	42,360.1		42,360.1		$ 41,603.4
Investments in unconsolidated affiliates	2,485.4		2,485.4		2,600.2
Intangible assets, net	3,348.6		3,348.6		3,449.0
Goodwill	5,745.2		5,745.2		5,745.2
Segment assets	53,939.3		53,939.3		53,397.8
NGL Pipelines & Services [Member]
Information by business segment [Abstract]
Total revenues	2,614.0	3,252.1	8,058.4	9,851.2
Equity in income (loss) of unconsolidated affiliates	29.3	25.9	90.8	82.7
Investments in unconsolidated affiliates	676.4		676.4		703.8
Intangible assets, net	341.2		341.2		360.2
Crude Oil Pipelines & Services [Member]
Information by business segment [Abstract]
Total revenues	1,521.6	2,478.3	5,023.7	7,952.2
Equity in income (loss) of unconsolidated affiliates	51.8	113.2	243.2	348.8
Investments in unconsolidated affiliates	1,774.8		1,774.8		1,866.5
Intangible assets, net	1,952.4		1,952.4		2,001.9
Natural Gas Pipelines & Services [Member]
Information by business segment [Abstract]
Total revenues	606.9	715.5	1,862.7	2,462.3
Equity in income (loss) of unconsolidated affiliates	1.4	1.6	4.3	4.9
Investments in unconsolidated affiliates	29.9		29.9		27.3
Intangible assets, net	915.1		915.1		941.2
Petrochemical & Refined Products Services [Member]
Information by business segment [Abstract]
Total revenues	2,179.5	1,518.2	5,210.7	4,518.2
Equity in income (loss) of unconsolidated affiliates	(0.5)	(1.4)	(2.2)	(5.1)
Investments in unconsolidated affiliates	4.3		4.3		2.6
Intangible assets, net	139.9		139.9		145.7
Reportable Business Segments [Member] | NGL Pipelines & Services [Member]
Information by business segment [Abstract]
Segment gross operating margin	1,028.1	1,008.3	3,038.2	2,933.8
Mark-to-market gains (losses) in gross operating margin	(12.0)	(0.7)	11.4	(0.1)
Revenues from third parties	2,612.4	3,250.1	8,053.4	9,843.9
Revenues from related parties	1.6	2.0	5.0	7.3
Intersegment and intrasegment revenues	7,098.2	4,729.3	18,826.6	14,715.5
Total revenues	9,712.2	7,981.4	26,885.0	24,566.7
Equity in income (loss) of unconsolidated affiliates	29.3	25.9	90.8	82.7
Property, plant and equipment, net	17,309.6		17,309.6		16,652.1
Investments in unconsolidated affiliates	676.4		676.4		703.8
Intangible assets, net	341.2		341.2		360.2
Goodwill	2,651.7		2,651.7		2,651.7
Segment assets	20,978.9		20,978.9		20,367.8
Reportable Business Segments [Member] | Crude Oil Pipelines & Services [Member]
Information by business segment [Abstract]
Segment gross operating margin	481.8	496.2	1,569.1	1,671.7
Mark-to-market gains (losses) in gross operating margin	10.1	9.8	28.9	95.0
Revenues from third parties	1,518.0	2,467.9	5,007.0	7,916.5
Revenues from related parties	3.6	10.4	16.7	35.7
Intersegment and intrasegment revenues	6,422.5	9,479.7	18,302.7	26,818.0
Total revenues	7,944.1	11,958.0	23,326.4	34,770.2
Equity in income (loss) of unconsolidated affiliates	51.8	113.2	243.2	348.8
Property, plant and equipment, net	6,503.6		6,503.6		6,324.4
Investments in unconsolidated affiliates	1,774.8		1,774.8		1,866.5
Intangible assets, net	1,952.4		1,952.4		2,001.9
Goodwill	1,841.0		1,841.0		1,841.0
Segment assets	12,071.8		12,071.8		12,033.8
Reportable Business Segments [Member] | Natural Gas Pipelines & Services [Member]
Information by business segment [Abstract]
Segment gross operating margin	208.4	258.5	701.1	824.6
Mark-to-market gains (losses) in gross operating margin	(14.8)	1.3	10.0	1.3
Revenues from third parties	604.6	712.3	1,855.2	2,451.6
Revenues from related parties	2.3	3.2	7.5	10.7
Intersegment and intrasegment revenues	117.0	141.7	325.0	500.2
Total revenues	723.9	857.2	2,187.7	2,962.5
Equity in income (loss) of unconsolidated affiliates	1.4	1.6	4.3	4.9
Property, plant and equipment, net	8,383.0		8,383.0		8,432.5
Investments in unconsolidated affiliates	29.9		29.9		27.3
Intangible assets, net	915.1		915.1		941.2
Goodwill	296.3		296.3		296.3
Segment assets	9,624.3		9,624.3		9,697.3
Reportable Business Segments [Member] | Petrochemical & Refined Products Services [Member]
Information by business segment [Abstract]
Segment gross operating margin	315.0	288.4	785.0	835.9
Mark-to-market gains (losses) in gross operating margin	(21.0)	(1.3)	3.4	(3.3)
Revenues from third parties	2,179.5	1,518.2	5,210.7	4,518.2
Revenues from related parties	0.0	0.0	0.0	0.0
Intersegment and intrasegment revenues	1,297.8	558.1	2,815.6	1,890.4
Total revenues	3,477.3	2,076.3	8,026.3	6,408.6
Equity in income (loss) of unconsolidated affiliates	(0.5)	(1.4)	(2.2)	(5.1)
Property, plant and equipment, net	7,695.0		7,695.0		7,553.2
Investments in unconsolidated affiliates	4.3		4.3		2.6
Intangible assets, net	139.9		139.9		145.7
Goodwill	956.2		956.2		956.2
Segment assets	8,795.4		8,795.4		8,657.7
Eliminations [Member]
Information by business segment [Abstract]
Revenues from third parties	0.0	0.0	0.0	0.0
Revenues from related parties	0.0	0.0	0.0	0.0
Intersegment and intrasegment revenues	(14,935.5)	(14,908.8)	(40,269.9)	(43,924.1)
Total revenues	(14,935.5)	(14,908.8)	(40,269.9)	(43,924.1)
Equity in income (loss) of unconsolidated affiliates	0.0	$ 0.0	0.0	$ 0.0
Adjustments [Member]
Information by business segment [Abstract]
Property, plant and equipment, net	2,468.9		2,468.9		2,641.2
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	$ 2,468.9		$ 2,468.9		$ 2,641.2