Inventories (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Inventory by Product Type [Abstract]
NGLs		$ 840.0		$ 840.0		$ 1,094.9
Petrochemicals and refined products		649.9		649.9		311.5
Crude oil		519.3		519.3		674.2
Natural gas		14.9		14.9		10.8
Total		2,024.1		2,024.1		$ 2,091.4
Summary of cost of sales and lower of cost or net realizable value adjustments [Abstract]
Cost of sales	[1]	3,195.2	$ 5,609.4	8,018.2	$ 11,445.0
Lower of cost or net realizable value adjustments recognized in cost of sales		$ 13.2	$ 4.9	$ 51.2	$ 10.3

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