Equity and Distributions, Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Abstract]
Beginning balance	$ (171.7)	$ (280.0)
Other comprehensive income (loss) before reclassifications	14.5	147.1
Amounts reclassified from accumulated other comprehensive loss (income)	(4.0)	16.7
Total other comprehensive income (loss)	10.5	163.8
Ending balance	(161.2)	(116.2)
Interest expense	252.1	249.3
Revenue	(9,298.5)	(7,320.4)
Operating costs and expenses	8,222.7	6,333.2
Total	(911.5)	(771.0)
Gains (Losses) on Cash Flow Hedges [Member] | Interest Rate Derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Beginning balance	(165.1)	(199.8)
Other comprehensive income (loss) before reclassifications	11.1	2.4
Amounts reclassified from accumulated other comprehensive loss (income)	10.5	9.6
Total other comprehensive income (loss)	21.6	12.0
Ending balance	(143.5)	(187.8)
Gains (Losses) on Cash Flow Hedges [Member] | Commodity Derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Beginning balance	(10.1)	(83.8)
Other comprehensive income (loss) before reclassifications	3.4	144.8
Amounts reclassified from accumulated other comprehensive loss (income)	(14.5)	7.1
Total other comprehensive income (loss)	(11.1)	151.9
Ending balance	(21.2)	68.1
Other [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Beginning balance	3.5	3.6
Other comprehensive income (loss) before reclassifications	0.0	(0.1)
Amounts reclassified from accumulated other comprehensive loss (income)	0.0	0.0
Total other comprehensive income (loss)	0.0	(0.1)
Ending balance	3.5	3.5
Reclassification out of Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Total	(4.0)	16.7
Reclassification out of Accumulated Other Comprehensive Income (Loss) [Member] | Gains (Losses) on Cash Flow Hedges [Member] | Interest Rate Derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Interest expense	10.5	9.6
Reclassification out of Accumulated Other Comprehensive Income (Loss) [Member] | Gains (Losses) on Cash Flow Hedges [Member] | Commodity Derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Revenue	(14.0)	7.5
Operating costs and expenses	$ (0.5)	$ (0.4)