Property, Plant and Equipment and Intangible Assets - Property, Plant and Equipment (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 18,189.3	$ 17,220.7
Accumulated depreciation and amortization	(4,485.9)	(4,292.3)
Property, plant and equipment, net	13,703.4	12,928.4
Intangible assets	2,736.6	2,736.6
Accumulated amortization	(796.4)	(753.4)
Intangible assets, net	$ 1,940.2	1,983.2
Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	10 years
Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	20 years
Gathering Systems [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 8,427.6	7,547.9
Gathering Systems [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	5 years
Gathering Systems [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	20 years
Processing and Fractionation Facilities [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 4,294.1	4,007.7
Processing and Fractionation Facilities [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	5 years
Processing and Fractionation Facilities [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	25 years
Terminaling and Storage Facilities [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 1,173.0	1,138.7
Terminaling and Storage Facilities [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	5 years
Terminaling and Storage Facilities [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	25 years
Transportation Assets [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 1,016.8	445.1
Transportation Assets [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	10 years
Transportation Assets [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	25 years
Other Property, Plant and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 398.9	334.5
Other Property, Plant and Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	3 years
Other Property, Plant and Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	25 years
Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 149.3	144.3
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	2,688.7	$ 3,602.5
Finance Lease Right-of-Use Assets [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 40.9