Intangible Assets and Goodwill, Intangible Assets (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Identifiable intangible assets [Abstract]
Gross Value	$ 2,612.2		$ 2,612.2		$ 2,616.8
Accumulated Amortization	(1,124.6)		(1,124.6)		(1,050.0)
Carrying Value	1,487.6		1,487.6		1,566.8
Amortization Expense	26.6	32.3	80.2	95.9
Forecasted amortization expense [Abstract]
Remainder of 2013	25.5		25.5
2014	96.3		96.3
2015	90.4		90.4
2016	92.1		92.1
2017	96.1		96.1
NGL Pipelines & Services [Member]
Identifiable intangible assets [Abstract]
Gross Value	622.1		622.1		625.4
Accumulated Amortization	(328.2)		(328.2)		(304.8)
Carrying Value	293.9		293.9		320.6
Amortization Expense	8.6	10.1	27.7	29.9
NGL Pipelines & Services [Member] | Customer relationship intangibles [Member]
Identifiable intangible assets [Abstract]
Gross Value	340.8		340.8		340.8
Accumulated Amortization	(161.3)		(161.3)		(147.6)
Carrying Value	179.5		179.5		193.2
NGL Pipelines & Services [Member] | Contract-based intangibles [Member]
Identifiable intangible assets [Abstract]
Gross Value	281.3		281.3		284.6
Accumulated Amortization	(166.9)		(166.9)		(157.2)
Carrying Value	114.4		114.4		127.4
Onshore Natural Gas Pipelines & Services [Member]
Identifiable intangible assets [Abstract]
Gross Value	1,629.7		1,629.7		1,629.7
Accumulated Amortization	(599.8)		(599.8)		(561.8)
Carrying Value	1,029.9		1,029.9		1,067.9
Amortization Expense	13.3	16.8	38.0	48.4
Onshore Natural Gas Pipelines & Services [Member] | Customer relationship intangibles [Member]
Identifiable intangible assets [Abstract]
Gross Value	1,163.6		1,163.6		1,163.6
Accumulated Amortization	(273.8)		(273.8)		(250.0)
Carrying Value	889.8		889.8		913.6
Onshore Natural Gas Pipelines & Services [Member] | Contract-based intangibles [Member]
Identifiable intangible assets [Abstract]
Gross Value	466.1		466.1		466.1
Accumulated Amortization	(326.0)		(326.0)		(311.8)
Carrying Value	140.1		140.1		154.3
Onshore Crude Oil Pipelines & Services [Member]
Identifiable intangible assets [Abstract]
Gross Value	11.1		11.1		11.1
Accumulated Amortization	(6.2)		(6.2)		(5.2)
Carrying Value	4.9		4.9		5.9
Amortization Expense	0.3	0.2	1.0	0.5
Onshore Crude Oil Pipelines & Services [Member] | Customer relationship intangibles [Member]
Identifiable intangible assets [Abstract]
Gross Value	10.7		10.7		10.7
Accumulated Amortization	(5.9)		(5.9)		(4.9)
Carrying Value	4.8		4.8		5.8
Onshore Crude Oil Pipelines & Services [Member] | Contract-based intangibles [Member]
Identifiable intangible assets [Abstract]
Gross Value	0.4		0.4		0.4
Accumulated Amortization	(0.3)		(0.3)		(0.3)
Carrying Value	0.1		0.1		0.1
Offshore Pipelines & Services [Member]
Identifiable intangible assets [Abstract]
Gross Value	205.1		205.1		205.1
Accumulated Amortization	(147.7)		(147.7)		(138.9)
Carrying Value	57.4		57.4		66.2
Amortization Expense	2.9	3.1	8.8	8.3
Offshore Pipelines & Services [Member] | Customer relationship intangibles [Member]
Identifiable intangible assets [Abstract]
Gross Value	203.9		203.9		203.9
Accumulated Amortization	(147.3)		(147.3)		(138.5)
Carrying Value	56.6		56.6		65.4
Offshore Pipelines & Services [Member] | Contract-based intangibles [Member]
Identifiable intangible assets [Abstract]
Gross Value	1.2		1.2		1.2
Accumulated Amortization	(0.4)		(0.4)		(0.4)
Carrying Value	0.8		0.8		0.8
Petrochemical & Refined Products Services [Member]
Identifiable intangible assets [Abstract]
Gross Value	144.2		144.2		145.5
Accumulated Amortization	(42.7)		(42.7)		(39.3)
Carrying Value	101.5		101.5		106.2
Amortization Expense	1.5	2.1	4.7	8.8
Petrochemical & Refined Products Services [Member] | Customer relationship intangibles [Member]
Identifiable intangible assets [Abstract]
Gross Value	104.3		104.3		104.3
Accumulated Amortization	(37.1)		(37.1)		(33.4)
Carrying Value	67.2		67.2		70.9
Petrochemical & Refined Products Services [Member] | Contract-based intangibles [Member]
Identifiable intangible assets [Abstract]
Gross Value	39.9		39.9		41.2
Accumulated Amortization	(5.6)		(5.6)		(5.9)
Carrying Value	$ 34.3		$ 34.3		$ 35.3