Intangible Assets and Goodwill, Intangible Assets (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Identifiable intangible assets [Abstract]
Gross Value	$ 2,612.2	$ 2,616.8
Accumulated Amortization	(1,150.0)	(1,050.0)
Carrying Value	1,462.2	1,566.8	1,656.2
Amortization Expense	105.6	125.7	147.0
Forecasted amortization expense [Abstract]
2014	93.8
2015	85.6
2016	81.2
2017	85.7
2018	89.0
Customer relationship intangibles [Member]
Identifiable intangible assets [Abstract]
Carrying Value	1,180.0
Contract-based intangibles [Member]
Identifiable intangible assets [Abstract]
Carrying Value	280.3
NGL Pipelines & Services [Member]
Identifiable intangible assets [Abstract]
Gross Value	622.1	625.4
Accumulated Amortization	(336.9)	(304.8)
Carrying Value	285.2	320.6	341.3
Amortization Expense	36.4	39.7	41.1
NGL Pipelines & Services [Member] | Customer relationship intangibles [Member]
Identifiable intangible assets [Abstract]
Gross Value	340.8	340.8
Accumulated Amortization	(165.7)	(147.6)
Carrying Value	175.1	193.2
NGL Pipelines & Services [Member] | Contract-based intangibles [Member]
Identifiable intangible assets [Abstract]
Gross Value	281.3	284.6
Accumulated Amortization	(171.2)	(157.2)
Carrying Value	110.1	127.4
Onshore Natural Gas Pipelines & Services [Member]
Identifiable intangible assets [Abstract]
Gross Value	1,629.7	1,629.7
Accumulated Amortization	(611.9)	(561.8)
Carrying Value	1,017.8	1,067.9	1,127.8
Amortization Expense	50.1	63.4	77.1
Onshore Natural Gas Pipelines & Services [Member] | Customer relationship intangibles [Member]
Identifiable intangible assets [Abstract]
Gross Value	1,163.6	1,163.6
Accumulated Amortization	(281.2)	(250.0)
Carrying Value	882.4	913.6
Onshore Natural Gas Pipelines & Services [Member] | Contract-based intangibles [Member]
Identifiable intangible assets [Abstract]
Gross Value	466.1	466.1
Accumulated Amortization	(330.7)	(311.8)
Carrying Value	135.4	154.3
Onshore Crude Oil Pipelines & Services [Member]
Identifiable intangible assets [Abstract]
Gross Value	11.1	11.1
Accumulated Amortization	(6.6)	(5.2)
Carrying Value	4.5	5.9	5.8
Amortization Expense	1.4	0.9	0.4
Onshore Crude Oil Pipelines & Services [Member] | Customer relationship intangibles [Member]
Identifiable intangible assets [Abstract]
Gross Value	10.7	10.7
Accumulated Amortization	(6.3)	(4.9)
Carrying Value	4.4	5.8
Onshore Crude Oil Pipelines & Services [Member] | Contract-based intangibles [Member]
Identifiable intangible assets [Abstract]
Gross Value	0.4	0.4
Accumulated Amortization	(0.3)	(0.3)
Carrying Value	0.1	0.1
Offshore Pipelines & Services [Member]
Identifiable intangible assets [Abstract]
Gross Value	205.1	205.1
Accumulated Amortization	(150.4)	(138.9)
Carrying Value	54.7	66.2	77.5
Amortization Expense	11.5	11.3	11.2
Offshore Pipelines & Services [Member] | Customer relationship intangibles [Member]
Identifiable intangible assets [Abstract]
Gross Value	203.9	203.9
Accumulated Amortization	(150.0)	(138.5)
Carrying Value	53.9	65.4
Offshore Pipelines & Services [Member] | Contract-based intangibles [Member]
Identifiable intangible assets [Abstract]
Gross Value	1.2	1.2
Accumulated Amortization	(0.4)	(0.4)
Carrying Value	0.8	0.8
Petrochemical & Refined Products Services [Member]
Identifiable intangible assets [Abstract]
Gross Value	144.2	145.5
Accumulated Amortization	(44.2)	(39.3)
Carrying Value	100.0	106.2	103.8
Amortization Expense	6.2	10.4	17.2
Petrochemical & Refined Products Services [Member] | Customer relationship intangibles [Member]
Identifiable intangible assets [Abstract]
Gross Value	104.3	104.3
Accumulated Amortization	(38.2)	(33.4)
Carrying Value	66.1	70.9
Petrochemical & Refined Products Services [Member] | Contract-based intangibles [Member]
Identifiable intangible assets [Abstract]
Gross Value	39.9	41.2
Accumulated Amortization	(6.0)	(5.9)
Carrying Value	$ 33.9	$ 35.3