Business Segments, Consolidated Revenues and Expenses (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Consolidated Revenues [Abstract]
Total consolidated revenues		$ 6,607.6	$ 5,617.8	$ 13,928.0	$ 10,623.1
Operating costs and expenses:
Cost of sales	[1]	4,731.1	3,838.7	10,066.8	7,047.0
Other operating costs and expenses	[2]	605.6	601.3	1,216.0	1,175.1
Depreciation, amortization and accretion		379.2	360.3	755.4	718.5
Asset impairment and related charges		14.0	20.2	25.2	21.9
Net losses attributable to asset sales		0.3	1.7	0.0	6.6
General and administrative costs		45.7	35.1	96.1	79.0
Total consolidated costs and expenses		5,775.9	4,857.3	12,159.5	9,048.1
NGL Pipelines & Services [Member]
Consolidated Revenues [Abstract]
Sales of NGLs and related products		2,158.0	2,060.4	5,045.2	4,003.9
Midstream services		462.6	455.1	921.2	915.4
Total consolidated revenues		2,620.6	2,515.5	5,966.4	4,919.3
Crude Oil Pipelines & Services [Member]
Consolidated Revenues [Abstract]
Sales of crude oil		1,705.1	1,482.2	3,323.7	2,603.3
Midstream services		194.5	177.8	383.1	345.3
Total consolidated revenues		1,899.6	1,660.0	3,706.8	2,948.6
Natural Gas Pipelines & Services [Member]
Consolidated Revenues [Abstract]
Sales of natural gas		560.6	305.7	1,104.6	620.7
Midstream services		225.6	230.0	442.8	465.0
Total consolidated revenues		786.2	535.7	1,547.4	1,085.7
Petrochemical & Refined Products Services [Member]
Consolidated Revenues [Abstract]
Sales of petrochemicals and refined products		1,114.1	713.4	2,325.2	1,266.6
Midstream services		187.1	193.2	382.2	402.9
Total consolidated revenues		$ 1,301.2	$ 906.6	$ 2,707.4	$ 1,669.5

[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.