Equity and Distributions, Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Abstract]
Beginning Balance				$ (219.2)				$ (241.6)	$ (219.2)	$ (241.6)
Other comprehensive income (loss) before reclassifications									(151.6)	215.3
Amounts reclassified from accumulated other comprehensive (income) loss									90.8	(192.9)
Total other comprehensive income (loss)									(60.8)	22.4	$ 117.4
Ending Balance	$ (280.0)				$ (219.2)				(280.0)	(219.2)	(241.6)
Interest expense									982.6	961.8	921.0
Operating costs and expenses									19,643.5	23,668.7	44,220.5
Total	(669.7)	$ (643.1)	$ (570.0)	(670.2)	(693.5)	$ (657.7)	$ (556.6)	(650.6)	(2,553.0)	(2,558.4)	(2,833.5)
Gains and Losses on Cash Flow Hedges [Member] | Commodity Derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Beginning Balance				56.6				69.9	56.6	69.9
Other comprehensive income (loss) before reclassifications									(193.8)	214.9
Amounts reclassified from accumulated other comprehensive (income) loss									53.4	(228.2)
Total other comprehensive income (loss)									(140.4)	(13.3)
Ending Balance	(83.8)				56.6				(83.8)	56.6	69.9
Gains and Losses on Cash Flow Hedges [Member] | Interest Rate Derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Beginning Balance				(279.5)				(314.8)	(279.5)	(314.8)
Other comprehensive income (loss) before reclassifications									42.3	0.0
Amounts reclassified from accumulated other comprehensive (income) loss									37.4	35.3
Total other comprehensive income (loss)									79.7	35.3
Ending Balance	(199.8)				(279.5)				(199.8)	(279.5)	(314.8)
Other [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Beginning Balance				$ 3.7				$ 3.3	3.7	3.3
Other comprehensive income (loss) before reclassifications									(0.1)	0.4
Amounts reclassified from accumulated other comprehensive (income) loss									0.0	0.0
Total other comprehensive income (loss)									(0.1)	0.4
Ending Balance	$ 3.6				$ 3.7				3.6	3.7	$ 3.3
Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Total									90.8	(192.9)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Commodity Derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Revenue									53.6	(231.7)
Operating costs and expenses									(0.2)	3.5
Reclassification out of Accumulated Other Comprehensive Income [Member] | Interest Rate Derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Interest expense									$ 37.4	$ 35.3