Revenues, Revenues by Business Segment and Revenue Type (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenue [Abstract]
Revenues	$ 5,751.0	$ 8,276.3	$ 13,233.5	$ 16,819.8
NGL Pipelines & Services [Member]
Revenue [Abstract]
Revenues	2,476.3	3,284.7	5,444.4	6,599.1
NGL Pipelines & Services [Member] | Sales of NGLs and Related Products [Member]
Revenue [Abstract]
Revenues	1,934.1	2,659.4	4,353.3	5,330.6
NGL Pipelines & Services [Member] | Midstream Services [Member]
Revenue [Abstract]
Revenues	542.2	625.3	1,091.1	1,268.5
NGL Pipelines & Services [Member] | Midstream Services: Natural Gas Processing and Fractionation [Member]
Revenue [Abstract]
Revenues	181.9	288.2	370.4	557.7
NGL Pipelines & Services [Member] | Midstream Services: Transportation [Member]
Revenue [Abstract]
Revenues	249.9	243.9	514.9	519.2
NGL Pipelines & Services [Member] | Midstream Services: Storage and Terminals [Member]
Revenue [Abstract]
Revenues	110.4	93.2	205.8	191.6
Crude Oil Pipelines & Services [Member]
Revenue [Abstract]
Revenues	1,463.2	2,866.6	3,502.1	5,473.9
Crude Oil Pipelines & Services [Member] | Sales of Crude Oil [Member]
Revenue [Abstract]
Revenues	1,146.7	2,531.7	2,843.6	4,860.1
Crude Oil Pipelines & Services [Member] | Midstream Services [Member]
Revenue [Abstract]
Revenues	316.5	334.9	658.5	613.8
Crude Oil Pipelines & Services [Member] | Midstream Services: Transportation [Member]
Revenue [Abstract]
Revenues	195.8	205.3	414.2	389.0
Crude Oil Pipelines & Services [Member] | Midstream Services: Storage and Terminals [Member]
Revenue [Abstract]
Revenues	120.7	129.6	244.3	224.8
Natural Gas Pipelines & Services [Member]
Revenue [Abstract]
Revenues	585.2	819.3	1,255.8	1,746.8
Natural Gas Pipelines & Services [Member] | Sales of Natural Gas [Member]
Revenue [Abstract]
Revenues	347.7	531.4	746.9	1,187.1
Natural Gas Pipelines & Services [Member] | Midstream Services [Member]
Revenue [Abstract]
Revenues	237.5	287.9	508.9	559.7
Natural Gas Pipelines & Services [Member] | Midstream Services: Transportation [Member]
Revenue [Abstract]
Revenues	237.5	287.9	508.9	559.7
Petrochemical & Refined Products Services [Member]
Revenue [Abstract]
Revenues	1,226.3	1,305.7	3,031.2	3,000.0
Petrochemical & Refined Products Services [Member] | Sales of Petrochemicals and Refined Products [Member]
Revenue [Abstract]
Revenues	1,030.0	1,087.7	2,627.5	2,568.3
Petrochemical & Refined Products Services [Member] | Midstream Services [Member]
Revenue [Abstract]
Revenues	196.3	218.0	403.7	431.7
Petrochemical & Refined Products Services [Member] | Midstream Services: Fractionation and Isomerization [Member]
Revenue [Abstract]
Revenues	38.6	41.5	74.4	82.3
Petrochemical & Refined Products Services [Member] | Midstream Services: Transportation [Member]
Revenue [Abstract]
Revenues	115.4	132.2	250.3	258.8
Petrochemical & Refined Products Services [Member] | Midstream Services: Storage and Terminals [Member]
Revenue [Abstract]
Revenues	$ 42.3	$ 44.3	$ 79.0	$ 90.6