Revenues, Revenues by Business Segment and Revenue Type (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenue [Abstract]
Revenues	$ 8,276.3	$ 8,467.5	$ 16,819.8	$ 17,766.0
Sales of Products [Member] | Revenues [Member] | Product Concentration Risk [Member]
Revenue [Abstract]
Concentration risk percentage	82.00%	84.00%	83.00%	85.00%
Midstream Services [Member] | Revenues [Member] | Product Concentration Risk [Member]
Revenue [Abstract]
Concentration risk percentage	18.00%	16.00%	17.00%	15.00%
NGL Pipelines & Services [Member]
Revenue [Abstract]
Revenues	$ 3,284.7	$ 3,273.7	$ 6,599.1	$ 6,687.0
NGL Pipelines & Services [Member] | Sales of NGLs and Related Products [Member]
Revenue [Abstract]
Revenues	2,659.4	2,610.9	5,330.6	5,426.3
NGL Pipelines & Services [Member] | Midstream Services [Member]
Revenue [Abstract]
Revenues	625.3	662.8	1,268.5	1,260.7
NGL Pipelines & Services [Member] | Midstream Services: Natural Gas Processing and Fractionation [Member]
Revenue [Abstract]
Revenues	288.2	332.6	557.7	585.0
NGL Pipelines & Services [Member] | Midstream Services: Transportation [Member]
Revenue [Abstract]
Revenues	243.9	228.3	519.2	483.7
NGL Pipelines & Services [Member] | Midstream Services: Storage and Terminals [Member]
Revenue [Abstract]
Revenues	93.2	101.9	191.6	192.0
Crude Oil Pipelines & Services [Member]
Revenue [Abstract]
Revenues	2,866.6	2,781.2	5,473.9	6,352.1
Crude Oil Pipelines & Services [Member] | Sales of Crude Oil [Member]
Revenue [Abstract]
Revenues	2,531.7	2,532.2	4,860.1	5,873.9
Crude Oil Pipelines & Services [Member] | Midstream Services [Member]
Revenue [Abstract]
Revenues	334.9	249.0	613.8	478.2
Crude Oil Pipelines & Services [Member] | Midstream Services: Transportation [Member]
Revenue [Abstract]
Revenues	205.3	161.1	389.0	302.8
Crude Oil Pipelines & Services [Member] | Midstream Services: Storage and Terminals [Member]
Revenue [Abstract]
Revenues	129.6	87.9	224.8	175.4
Natural Gas Pipelines & Services [Member]
Revenue [Abstract]
Revenues	819.3	792.8	1,746.8	1,597.6
Natural Gas Pipelines & Services [Member] | Sales of Natural Gas [Member]
Revenue [Abstract]
Revenues	531.4	532.5	1,187.1	1,092.5
Natural Gas Pipelines & Services [Member] | Midstream Services [Member]
Revenue [Abstract]
Revenues	287.9	260.3	559.7	505.1
Natural Gas Pipelines & Services [Member] | Midstream Services: Transportation [Member]
Revenue [Abstract]
Revenues	287.9	260.3	559.7	505.1
Petrochemical & Refined Products Services [Member]
Revenue [Abstract]
Revenues	1,305.7	1,619.8	3,000.0	3,129.3
Petrochemical & Refined Products Services [Member] | Sales of Petrochemicals and Refined Products [Member]
Revenue [Abstract]
Revenues	1,087.7	1,413.4	2,568.3	2,702.7
Petrochemical & Refined Products Services [Member] | Midstream Services [Member]
Revenue [Abstract]
Revenues	218.0	206.4	431.7	426.6
Petrochemical & Refined Products Services [Member] | Midstream Services: Fractionation and Isomerization [Member]
Revenue [Abstract]
Revenues	41.5	45.2	82.3	100.9
Petrochemical & Refined Products Services [Member] | Midstream Services: Transportation [Member]
Revenue [Abstract]
Revenues	132.2	114.2	258.8	233.8
Petrochemical & Refined Products Services [Member] | Midstream Services: Storage and Terminals [Member]
Revenue [Abstract]
Revenues	$ 44.3	$ 47.0	$ 90.6	$ 91.9