Business Segments, Segment Reporting Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Information by business segment [Abstract]
Segment gross operating margin	$ 2,086.2	$ 1,461.7	$ 4,214.6	$ 3,036.4
Mark-to-market gains (losses) in gross operating margin	(12.5)	(322.1)	83.8	(458.9)
Mark-to-market loss in interest expense	0.0	0.0	0.0	(0.1)
Total mark-to-market gains (losses)	(12.5)	(322.1)	83.8	(459.0)
Revenues from third parties	8,250.5	8,411.9	16,781.7	17,685.7
Revenues from related parties	25.8	55.6	38.1	80.3
Intersegment and intrasegment revenues	0.0	0.0	0.0	0.0
Total revenues	8,276.3	8,467.5	16,819.8	17,766.0
Equity in income (loss) of unconsolidated affiliates	137.4	122.3	292.0	238.0
Property, plant and equipment, net	40,089.1		40,089.1		$ 38,737.6
Investments in unconsolidated affiliates	2,652.1		2,652.1		2,615.1
Intangible assets, net	3,532.6		3,532.6		3,608.4
Goodwill	5,745.2		5,745.2		5,745.2
Segment assets	52,019.0		52,019.0		50,706.3
NGL Pipelines & Services [Member]
Information by business segment [Abstract]
Total revenues	3,284.7	3,273.7	6,599.1	6,687.0
Equity in income (loss) of unconsolidated affiliates	26.7	39.4	56.8	58.8
Investments in unconsolidated affiliates	686.7		686.7		662.0
Intangible assets, net	374.0		374.0		380.1
Crude Oil Pipelines & Services [Member]
Information by business segment [Abstract]
Total revenues	2,866.6	2,781.2	5,473.9	6,352.1
Equity in income (loss) of unconsolidated affiliates	111.0	83.5	235.6	181.4
Investments in unconsolidated affiliates	1,881.9		1,881.9		1,867.5
Intangible assets, net	2,048.5		2,048.5		2,094.6
Natural Gas Pipelines & Services [Member]
Information by business segment [Abstract]
Total revenues	819.3	792.8	1,746.8	1,597.6
Equity in income (loss) of unconsolidated affiliates	1.6	1.6	3.3	2.6
Investments in unconsolidated affiliates	24.0		24.0		22.8
Intangible assets, net	960.1		960.1		979.3
Petrochemical & Refined Products Services [Member]
Information by business segment [Abstract]
Total revenues	1,305.7	1,619.8	3,000.0	3,129.3
Equity in income (loss) of unconsolidated affiliates	(1.9)	(2.2)	(3.7)	(4.8)
Investments in unconsolidated affiliates	59.5		59.5		62.8
Intangible assets, net	150.0		150.0		154.4
Reportable Business Segments [Member] | NGL Pipelines & Services [Member]
Information by business segment [Abstract]
Segment gross operating margin	966.3	913.7	1,925.5	1,798.6
Mark-to-market gains (losses) in gross operating margin	(0.7)	11.2	0.6	7.8
Revenues from third parties	3,282.2	3,268.8	6,593.8	6,678.4
Revenues from related parties	2.5	4.9	5.3	8.6
Intersegment and intrasegment revenues	4,494.8	6,004.6	9,986.2	12,569.5
Total revenues	7,779.5	9,278.3	16,585.3	19,256.5
Equity in income (loss) of unconsolidated affiliates	26.7	39.4	56.8	58.8
Property, plant and equipment, net	16,109.6		16,109.6		14,845.4
Investments in unconsolidated affiliates	686.7		686.7		662.0
Intangible assets, net	374.0		374.0		380.1
Goodwill	2,651.7		2,651.7		2,651.7
Segment assets	19,822.0		19,822.0		18,539.2
Reportable Business Segments [Member] | Crude Oil Pipelines & Services [Member]
Information by business segment [Abstract]
Segment gross operating margin	513.2	52.8	1,175.5	272.8
Mark-to-market gains (losses) in gross operating margin	(14.6)	(338.0)	85.2	(467.6)
Revenues from third parties	2,847.0	2,733.8	5,448.6	6,286.5
Revenues from related parties	19.6	47.4	25.3	65.6
Intersegment and intrasegment revenues	9,453.3	9,978.5	17,338.3	21,404.8
Total revenues	12,319.9	12,759.7	22,812.2	27,756.9
Equity in income (loss) of unconsolidated affiliates	111.0	83.5	235.6	181.4
Property, plant and equipment, net	6,293.5		6,293.5		5,847.7
Investments in unconsolidated affiliates	1,881.9		1,881.9		1,867.5
Intangible assets, net	2,048.5		2,048.5		2,094.6
Goodwill	1,841.0		1,841.0		1,841.0
Segment assets	12,064.9		12,064.9		11,650.8
Reportable Business Segments [Member] | Natural Gas Pipelines & Services [Member]
Information by business segment [Abstract]
Segment gross operating margin	301.8	213.4	566.1	411.3
Mark-to-market gains (losses) in gross operating margin	0.3	3.4	0.0	1.2
Revenues from third parties	815.6	789.5	1,739.3	1,591.5
Revenues from related parties	3.7	3.3	7.5	6.1
Intersegment and intrasegment revenues	163.1	165.0	358.5	335.9
Total revenues	982.4	957.8	2,105.3	1,933.5
Equity in income (loss) of unconsolidated affiliates	1.6	1.6	3.3	2.6
Property, plant and equipment, net	8,275.8		8,275.8		8,303.8
Investments in unconsolidated affiliates	24.0		24.0		22.8
Intangible assets, net	960.1		960.1		979.3
Goodwill	296.3		296.3		296.3
Segment assets	9,556.2		9,556.2		9,602.2
Reportable Business Segments [Member] | Petrochemical & Refined Products Services [Member]
Information by business segment [Abstract]
Segment gross operating margin	304.9	281.8	547.5	553.7
Mark-to-market gains (losses) in gross operating margin	2.5	1.3	(2.0)	(0.3)
Revenues from third parties	1,305.7	1,619.8	3,000.0	3,129.3
Revenues from related parties	0.0	0.0	0.0	0.0
Intersegment and intrasegment revenues	617.9	784.0	1,332.3	1,397.3
Total revenues	1,923.6	2,403.8	4,332.3	4,526.6
Equity in income (loss) of unconsolidated affiliates	(1.9)	(2.2)	(3.7)	(4.8)
Property, plant and equipment, net	6,179.6		6,179.6		6,213.9
Investments in unconsolidated affiliates	59.5		59.5		62.8
Intangible assets, net	150.0		150.0		154.4
Goodwill	956.2		956.2		956.2
Segment assets	7,345.3		7,345.3		7,387.3
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	(14,729.1)	(16,932.1)	(29,015.3)	(35,707.5)
Total revenues	(14,729.1)	(16,932.1)	(29,015.3)	(35,707.5)
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	3,230.6		3,230.6		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	$ 3,230.6		$ 3,230.6		$ 3,526.8