Equity and Distributions, Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 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			112.6	(19.5)
Reclassification of losses (gains) to net income during period			(331.1)	(42.1)
Total other comprehensive income (loss) for period	$ (269.4)	$ 83.3	(218.5)	(61.6)
Accumulated Other Comprehensive Income (Loss), Ending balance	(147.1)	(10.7)	(147.1)	(10.7)
Interest expense	320.2	290.1	637.7	567.3
Revenue	(5,751.0)	(8,276.3)	(13,233.5)	(16,819.8)
Operating costs and expenses	4,370.4	6,800.9	10,430.7	13,820.6
Total	(1,060.8)	(1,236.5)	(2,435.8)	(2,516.9)
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			(284.2)	(5.2)
Reclassification of losses (gains) to net income during period			33.2	18.4
Total other comprehensive income (loss) for period			(251.0)	13.2
Accumulated Other Comprehensive Income (Loss), Ending balance	(237.1)	(91.6)	(237.1)	(91.6)
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			396.9	(13.7)
Reclassification of losses (gains) to net income during period			(364.3)	(60.5)
Total other comprehensive income (loss) for period			32.6	(74.2)
Accumulated Other Comprehensive Income (Loss), Ending balance	87.7	78.5	87.7	78.5
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	2.3	2.4
Reclassification out of Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Total	(199.0)	7.0	(331.1)	(42.1)
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	9.7	9.2	33.2	18.4
Reclassification out of Accumulated Other Comprehensive Income (Loss) [Member] | Cash Flow Hedges [Member] | Commodity Derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Revenue	(209.8)	(2.5)	(364.2)	(67.8)
Operating costs and expenses	$ 1.1	$ 0.3	$ (0.1)	$ 7.3