Inventories (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013		Dec. 31, 2013
Available-for-Sale Inventory by Product Type [Abstract]
NGLs	$ 973.4				$ 973.4				$ 593.8
Petrochemicals and refined products	338.7				338.7				395.1
Crude oil	238.8				238.8				42.6
Natural gas	38.6				38.6				61.6
Total	1,589.5				1,589.5				1,093.1
Summary of cost of sales and lower of cost or market adjustments [Abstract]
Cost of sales	10,455.1	[1]	10,371.3	[1]	32,213.1	[1]	29,522.1	[1]
Lower of cost or market adjustments	$ 6.7		$ 4.5		$ 14.6		$ 14.9

[1] Cost of sales is a component of “Operating costs and expenses” as presented on our Unaudited Condensed Statements of Consolidated Operations. Period-to-period fluctuations in these amounts are primarily due to changes in energy commodity prices and sales volumes associated with our marketing activities.