Business Segments, Consolidated Revenues and Expenses (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Consolidated Revenues [Abstract]
Total consolidated revenues		$ 9,298.5	$ 7,320.4
Operating costs and expenses:
Cost of sales	[1]	7,140.4	5,335.7
Other operating costs and expenses	[2]	687.6	610.4
Depreciation, amortization and accretion		394.3	376.2
Asset impairment and related charges		0.9	11.2
Net gains attributable to asset sales		(0.5)	(0.3)
General and administrative costs		53.0	50.4
Total consolidated costs and expenses		8,275.7	6,383.6
NGL Pipelines & Services [Member]
Consolidated Revenues [Abstract]
Total consolidated revenues		3,413.3	3,345.8
Crude Oil Pipelines & Services [Member]
Consolidated Revenues [Abstract]
Total consolidated revenues		3,570.9	1,807.2
Natural Gas Pipelines & Services [Member]
Consolidated Revenues [Abstract]
Total consolidated revenues		804.8	761.2
Petrochemical & Refined Products Services [Member]
Consolidated Revenues [Abstract]
Total consolidated revenues		$ 1,509.5	$ 1,406.2

[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.

[2] Represents the cost of operating our plants, pipelines and other fixed assets excluding: depreciation, amortization and accretion charges; asset impairment and related charges; and net losses (or gains) attributable to asset sales.