Equity and Distributions, Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Abstract]
Accumulated Other Comprehensive Income (Loss), Beginning Balance				$ (171.7)				$ (280.0)	$ (171.7)		$ (280.0)
Other comprehensive income (loss) for period, before reclassifications									314.9		(44.3)
Reclassification of losses (gains) to net income during period									(92.3)		152.6
Total other comprehensive income (loss) for period									222.6		108.3		$ (60.8)
Accumulated Other Comprehensive Income (Loss), Ending balance	$ 50.9				$ (171.7)				50.9		(171.7)		(280.0)
Interest expense									1,096.7		984.6		982.6
Revenue	(9,182.3)	$ (9,585.9)	$ (8,467.5)	(9,298.5)	(8,426.6)	$ (6,886.9)	$ (6,607.6)	(7,320.4)	(36,534.2)	[1]	(29,241.5)	[2]	(23,022.3)	[2]
Operating costs and expenses									31,397.3		25,557.5		19,643.5
Total	(1,305.2)	$ (1,334.6)	$ (687.2)	(911.5)	(797.3)	$ (621.3)	$ (666.0)	(771.0)	(4,238.5)		(2,855.6)		(2,553.0)
Cash Flow Hedges [Member] | Commodity Derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Accumulated Other Comprehensive Income (Loss), Beginning Balance				(10.1)				(83.8)	(10.1)		(83.8)
Other comprehensive income (loss) for period, before reclassifications									293.2		(38.5)
Reclassification of losses (gains) to net income during period									(130.4)		112.2
Total other comprehensive income (loss) for period									162.8		73.7
Accumulated Other Comprehensive Income (Loss), Ending balance	152.7				(10.1)				152.7		(10.1)		(83.8)
Cash Flow Hedges [Member] | Interest Rate Derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Accumulated Other Comprehensive Income (Loss), Beginning Balance				(165.1)				(199.8)	(165.1)		(199.8)
Other comprehensive income (loss) for period, before reclassifications									22.2		(5.7)
Reclassification of losses (gains) to net income during period									38.1		40.4
Total other comprehensive income (loss) for period									60.3		34.7
Accumulated Other Comprehensive Income (Loss), Ending balance	(104.8)				(165.1)				(104.8)		(165.1)		(199.8)
Other [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Accumulated Other Comprehensive Income (Loss), Beginning Balance				$ 3.5				$ 3.6	3.5		3.6
Other comprehensive income (loss) for period, before reclassifications									(0.5)		(0.1)
Reclassification of losses (gains) to net income during period									0.0		0.0
Total other comprehensive income (loss) for period									(0.5)		(0.1)
Accumulated Other Comprehensive Income (Loss), Ending balance	$ 3.0				$ 3.5				3.0		3.5		$ 3.6
Reclassification out of Accumulated Other Comprehensive Income (Loss) [Member] | Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Total									(92.3)		152.6
Reclassification out of Accumulated Other Comprehensive Income (Loss) [Member] | Cash Flow Hedges [Member] | Commodity Derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Revenue									(131.7)		111.6
Operating costs and expenses									1.3		0.6
Reclassification out of Accumulated Other Comprehensive Income (Loss) [Member] | Cash Flow Hedges [Member] | Interest Rate Derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Interest expense									$ 38.1		$ 40.4

[1] Revenues are accounted for under ASC 606 upon implementation at January 1, 2018.

[2] Revenues are accounted for under ASC 605 for historical periods prior to January 1, 2018.