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, 2016	$ 22,266.0	$ (280.0)	$ 219.0	$ 22,327.0
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income	1,437.0	0.0	22.6	1,414.4
Cash distributions paid to limited partners	(1,757.8)	0.0	0.0	(1,757.8)
Cash payments made in connection with distribution equivalent rights	(7.2)	0.0	0.0	(7.2)
Cash distributions paid to noncontrolling interests	(23.1)	0.0	(23.1)	0.0
Cash contributions from noncontrolling interests	0.3	0.0	0.3	0.0
Net cash proceeds from the issuance of common units	757.2	0.0	0.0	757.2
Common units issued in connection with employee compensation	33.7	0.0	0.0	33.7
Amortization of fair value of equity-based awards	49.8	0.0	0.0	49.8
Cash flow hedges	151.4	151.4	0.0	0.0
Other	(27.1)	(0.1)	1.3	(28.3)
Balance at Jun. 30, 2017	22,880.2	(128.7)	220.1	22,788.8
Balance at Dec. 31, 2017	22,772.4	(171.7)	225.2	22,718.9
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income	1,598.7	0.0	24.2	1,574.5
Cash distributions paid to limited partners	(1,847.3)	0.0	0.0	(1,847.3)
Cash payments made in connection with distribution equivalent rights	(8.6)	0.0	0.0	(8.6)
Cash distributions paid to noncontrolling interests	(28.3)	0.0	(28.3)	0.0
Cash contributions from noncontrolling interests	206.9	0.0	206.9	0.0
Net cash proceeds from the issuance of common units	261.0	0.0	0.0	261.0
Common units issued in connection with employee compensation	39.1	0.0	0.0	39.1
Common units issued in connection with land acquisition	30.0	0.0	0.0	30.0
Amortization of fair value of equity-based awards	52.6	0.0	0.0	52.6
Cash flow hedges	49.0	49.0	0.0	0.0
Other	(35.0)	(0.5)	(9.1)	(25.4)
Balance at Jun. 30, 2018	$ 23,090.5	$ (123.2)	$ 418.9	$ 22,794.8