Inventories (Details) (USD $) In Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2011		Sep. 30, 2010		Sep. 30, 2011		Sep. 30, 2010		Dec. 31, 2010
Inventory amounts by product type [Abstract]
NGLs	$ 666.7				$ 666.7				$ 548.3
Petrochemicals and refined products	566.3				566.3				399.7
Crude oil	103.7				103.7				121.1
Natural gas	52.6				52.6				64.7
Other	0				0				0.2
Total	1,389.3				1,389.3				1,134.0
Summary of cost of sales and lower of cost or market adjustments [Abstract]
Cost of sales	9,787.6	[1]	6,814.0	[1]	28,397.2	[1]	20,499.5	[1]
Lower of cost or market adjustments	$ 5.1		$ 0.2		$ 6.8		$ 7.1

[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.