PROPERTY, PLANT AND EQUIPMENT (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	May. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property, plant and equipment		$ 19,543.8		$ 19,543.8			$ 18,467.9
Accumulated depreciation		(3,002.5)		(3,002.5)			(2,775.2)
Property, plant and equipment, net		16,541.3		16,541.3			15,692.7
Asset impairment charges		12.3		12.3
Tinsley Crude Oil Pipeline, Storage Facilities and Docks [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment						$ 16.8
Assets held for sale		4.5		4.5
Asset impairment charges		12.3
Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment		52.3		52.3			44.2
Rights-of-Way [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment		861.2		861.2			851.8
Pipelines [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment		9,726.6		9,726.6			9,585.4
Pumping Equipment, Buildings and Tanks [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	[1]	3,475.2		3,475.2			3,261.8
Amount reclassified		135.0
Compressors, Meters and Other Operating Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment		2,122.7		2,122.7			2,072.7
Vehicles, Office Furniture and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	[1]	313.4		313.4			278.9
Processing and Treating Plants [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment		629.3		629.3			516.0
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment		$ 2,363.1		$ 2,363.1			$ 1,857.1

[1] During the second quarter 2015, management reclassified $135.0 million related to rail facilities from “Vehicles, office furniture and equipment” to “Pumping equipment, buildings, and tanks” to better reflect the way in which these assets are analyzed. This change has been retrospectively adjusted for all periods presented.