Equity and Distributions, Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Abstract]
Beginning Balance				$ (241.6)				$ (359.0)	$ (241.6)	$ (359.0)
Other comprehensive income before reclassifications									215.3	161.7
Amounts reclassified from accumulated other comprehensive (income) loss									(192.9)	(44.3)
Total other comprehensive income (loss)									22.4	117.4	$ 11.4
Ending Balance	$ (219.2)				$ (241.6)				(219.2)	(241.6)	(359.0)
Interest expense									961.8	921.0	802.5
Operating costs and expenses									23,668.7	44,220.5	44,238.7
Total	(693.5)	$ (657.7)	$ (556.6)	(650.6)	(681.1)	$ (699.2)	$ (646.5)	(806.7)	(2,558.4)	(2,833.5)	(2,607.1)
Gains and Losses on Cash Flow Hedges [Member] | Commodity derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Beginning Balance				69.9				(14.7)	69.9	(14.7)
Other comprehensive income before reclassifications									214.9	161.3
Amounts reclassified from accumulated other comprehensive (income) loss									(228.2)	(76.7)
Total other comprehensive income (loss)									(13.3)	84.6
Ending Balance	56.6				69.9				56.6	69.9	(14.7)
Gains and Losses on Cash Flow Hedges [Member] | Interest rate derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Beginning Balance				(314.8)				(347.2)	(314.8)	(347.2)
Other comprehensive income before reclassifications									0.0	0.0
Amounts reclassified from accumulated other comprehensive (income) loss									35.3	32.4
Total other comprehensive income (loss)									35.3	32.4
Ending Balance	(279.5)				(314.8)				(279.5)	(314.8)	(347.2)
Other [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Beginning Balance				$ 3.3				$ 2.9	3.3	2.9
Other comprehensive income before reclassifications									0.4	0.4
Amounts reclassified from accumulated other comprehensive (income) loss									0.0	0.0
Total other comprehensive income (loss)									0.4	0.4
Ending Balance	$ 3.7				$ 3.3				3.7	3.3	$ 2.9
Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Total									(192.9)	(44.3)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Commodity derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Revenue									(231.7)	(75.0)
Operating costs and expenses									3.5	(1.7)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Interest rate derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Abstract]
Interest expense									$ 35.3	$ 32.4