UNAUDITED CONDENSED STATEMENTS OF CONSOLIDATED EQUITY - USD ($) $ in Millions	Total	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interests [Member]	Limited Partners [Member]
Balance at Dec. 31, 2015	$ 20,501.1	$ (219.2)	$ 206.0	$ 20,514.3
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income	670.2	0.0	9.0	661.2
Cash distributions paid to limited partners	(788.3)	0.0	0.0	(788.3)
Cash payments made in connection with distribution equivalent rights	(2.0)	0.0	0.0	(2.0)
Cash distributions paid to noncontrolling interests	(8.7)	0.0	(8.7)	0.0
Cash contributions from noncontrolling interests	11.1	0.0	11.1	0.0
Net cash proceeds from the issuance of common units	1,011.5	0.0	0.0	1,011.5
Amortization of fair value of equity-based awards	22.3	0.0	0.0	22.3
Cash flow hedges	(49.2)	(49.2)	0.0	0.0
Other	(21.7)	(0.1)	0.0	(21.6)
Balance at Mar. 31, 2016	21,346.3	(268.5)	217.4	21,397.4
Balance at Dec. 31, 2016	22,266.0	(280.0)	219.0	22,327.0
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income	771.0	0.0	10.3	760.7
Cash distributions paid to limited partners	(869.0)	0.0	0.0	(869.0)
Cash payments made in connection with distribution equivalent rights	(3.2)	0.0	0.0	(3.2)
Cash distributions paid to noncontrolling interests	(10.1)	0.0	(10.1)	0.0
Cash contributions from noncontrolling interests	0.2	0.0	0.2	0.0
Net cash proceeds from the issuance of common units	448.8	0.0	0.0	448.8
Common units issued in connection with employee compensation	33.7	0.0	0.0	33.7
Amortization of fair value of equity-based awards	24.8	0.0	0.0	24.8
Cash flow hedges	163.9	163.9	0.0	0.0
Other	(26.1)	(0.1)	1.3	(27.3)
Balance at Mar. 31, 2017	$ 22,800.0	$ (116.2)	$ 220.7	$ 22,695.5