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, 2014	$ 19,692.2	$ (241.6)	$ 1,629.0	$ 18,304.8
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income	1,864.9	0.0	28.5	1,836.4
Cash distributions paid to limited partners	(2,185.1)	0.0	0.0	(2,185.1)
Cash payments made in connection with distribution equivalent rights	(5.6)	0.0	0.0	(5.6)
Cash distributions paid to noncontrolling interests	(33.2)	0.0	(33.2)	0.0
Cash contributions from noncontrolling interests	37.4	0.0	37.4	0.0
Common units issued in connection with Step 2 of Oiltanking acquisition	0.0	0.0	(1,408.7)	1,408.7
Removal of noncontrolling interests in connection with sale of Offshore Business	(62.1)	0.0	(62.1)	0.0
Net cash proceeds from the issuance of common units	1,011.4	0.0	0.0	1,011.4
Amortization of fair value of equity-based awards	72.9	0.0	0.0	72.9
Cash flow hedges	10.5	10.5	0.0	0.0
Other	(50.4)	0.4	(0.1)	(50.7)
Balance at Sep. 30, 2015	20,352.9	(230.7)	190.8	20,392.8
Balance at Dec. 31, 2015	20,501.1	(219.2)	206.0	20,514.3
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income	1,883.3	0.0	29.0	1,854.3
Cash distributions paid to limited partners	(2,448.3)	0.0	0.0	(2,448.3)
Cash payments made in connection with distribution equivalent rights	(8.5)	0.0	0.0	(8.5)
Cash distributions paid to noncontrolling interests	(35.7)	0.0	(35.7)	0.0
Cash contributions from noncontrolling interests	20.1	0.0	20.1	0.0
Net cash proceeds from the issuance of common units	2,170.4	0.0	0.0	2,170.4
Amortization of fair value of equity-based awards	67.7	0.0	0.0	67.7
Cash flow hedges	(89.4)	(89.4)	0.0	0.0
Other	(22.0)	(0.1)	0.1	(22.0)
Balance at Sep. 30, 2016	$ 22,038.7	$ (308.7)	$ 219.5	$ 22,127.9