Equity and Distributions, Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Accumulated Other Comprehensive Income (Loss) [Abstract]
Accumulated Other Comprehensive Income (Loss), Beginning Balance	$ 71.4	$ 50.9
Other comprehensive income (loss) for period, before reclassifications	183.0	(95.8)
Reclassification of losses (gains) to net income during period	(132.1)	(49.1)
Total other comprehensive income (loss) for period	50.9	(144.9)
Accumulated Other Comprehensive Income (Loss), Ending balance	122.3	(94.0)
Interest expense	317.5	277.2
Revenue	(7,482.5)	(8,543.5)
Operating costs and expenses	6,060.3	7,019.7
Total	(1,375.0)	(1,280.4)
Cash Flow Hedges [Member] | Interest Rate Derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Accumulated Other Comprehensive Income (Loss), Beginning Balance	13.9	(104.8)
Other comprehensive income (loss) for period, before reclassifications	(292.0)	0.0
Reclassification of losses (gains) to net income during period	23.5	9.2
Total other comprehensive income (loss) for period	(268.5)	9.2
Accumulated Other Comprehensive Income (Loss), Ending balance	(254.6)	(95.6)
Cash Flow Hedges [Member] | Commodity Derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Accumulated Other Comprehensive Income (Loss), Beginning Balance	55.1	152.7
Other comprehensive income (loss) for period, before reclassifications	475.1	(95.2)
Reclassification of losses (gains) to net income during period	(155.6)	(58.3)
Total other comprehensive income (loss) for period	319.5	(153.5)
Accumulated Other Comprehensive Income (Loss), Ending balance	374.6	(0.8)
Other [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Accumulated Other Comprehensive Income (Loss), Beginning Balance	2.4	3.0
Other comprehensive income (loss) for period, before reclassifications	(0.1)	(0.6)
Reclassification of losses (gains) to net income during period	0.0	0.0
Total other comprehensive income (loss) for period	(0.1)	(0.6)
Accumulated Other Comprehensive Income (Loss), Ending balance	2.3	2.4
Reclassification out of Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Total	(132.1)	(49.1)
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	23.5	9.2
Reclassification out of Accumulated Other Comprehensive Income (Loss) [Member] | Cash Flow Hedges [Member] | Commodity Derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Revenue	(154.4)	(65.3)
Operating costs and expenses	$ (1.2)	$ 7.0