Derivative Instruments, Hedging Activities and Fair Value Measurements, Nonrecurring Fair Value Measurements (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Assets, Fair Value Disclosure [Abstract]
Non-cash asset impairment charges	$ 27.1	$ 9.1	$ 38.1	$ 14.5
Crude oil pipeline segments in Texas and Oklahoma [Member]
Assets, Fair Value Disclosure [Abstract]
Non-cash asset impairment charges			16.6	6.2
Refined products terminal and storage assets in Texas [Member]
Assets, Fair Value Disclosure [Abstract]
Non-cash asset impairment charges			10.0
Underground and other storage facilities [Member]
Assets, Fair Value Disclosure [Abstract]
Non-cash asset impairment charges			6.3
NGL fractionator in Texas [Member]
Assets, Fair Value Disclosure [Abstract]
Non-cash asset impairment charges				4.6
Tri-States Pipeline [Member]
Assets, Fair Value Disclosure [Abstract]
Non-cash asset impairment charges				2.9
Long-lived Assets Disposed of Other Than By Sale [Member]
Assets, Fair Value Disclosure [Abstract]
Non-cash asset impairment charges			29.8	14.2
Long-lived Assets Held and Used [Member]
Assets, Fair Value Disclosure [Abstract]
Non-cash asset impairment charges			4.2
Long-lived Assets Disposed of By Sale [Member]
Assets, Fair Value Disclosure [Abstract]
Non-cash asset impairment charges			4.1	0.3
Fair Value, Measurements, Nonrecurring [Member] \| Fair Value [Member]
Assets, Fair Value Disclosure [Abstract]
Assets, fair value	40.9	0	40.9	0
Fair Value, Measurements, Nonrecurring [Member] \| Fair Value [Member] \| Long-lived Assets Disposed of Other Than By Sale [Member]
Assets, Fair Value Disclosure [Abstract]
Assets, fair value	0	0	0	0
Fair Value, Measurements, Nonrecurring [Member] \| Fair Value [Member] \| Long-lived Assets Held and Used [Member]
Assets, Fair Value Disclosure [Abstract]
Assets, fair value	6.3		6.3
Fair Value, Measurements, Nonrecurring [Member] \| Fair Value [Member] \| Long-lived Assets Disposed of By Sale [Member]
Assets, Fair Value Disclosure [Abstract]
Assets, fair value	34.6	0	34.6	0
Fair Value, Measurements, Nonrecurring [Member] \| Fair Value [Member] \| Level 1 [Member] \| Long-lived Assets Disposed of Other Than By Sale [Member]
Assets, Fair Value Disclosure [Abstract]
Assets, fair value	0	0	0	0
Fair Value, Measurements, Nonrecurring [Member] \| Fair Value [Member] \| Level 1 [Member] \| Long-lived Assets Held and Used [Member]
Assets, Fair Value Disclosure [Abstract]
Assets, fair value	0		0
Fair Value, Measurements, Nonrecurring [Member] \| Fair Value [Member] \| Level 1 [Member] \| Long-lived Assets Disposed of By Sale [Member]
Assets, Fair Value Disclosure [Abstract]
Assets, fair value	33.8	0	33.8	0
Fair Value, Measurements, Nonrecurring [Member] \| Fair Value [Member] \| Level 2 [Member] \| Long-lived Assets Disposed of Other Than By Sale [Member]
Assets, Fair Value Disclosure [Abstract]
Assets, fair value	0	0	0	0
Fair Value, Measurements, Nonrecurring [Member] \| Fair Value [Member] \| Level 2 [Member] \| Long-lived Assets Held and Used [Member]
Assets, Fair Value Disclosure [Abstract]
Assets, fair value	0		0
Fair Value, Measurements, Nonrecurring [Member] \| Fair Value [Member] \| Level 2 [Member] \| Long-lived Assets Disposed of By Sale [Member]
Assets, Fair Value Disclosure [Abstract]
Assets, fair value	0	0	0	0
Fair Value, Measurements, Nonrecurring [Member] \| Fair Value [Member] \| Level 3 [Member] \| Long-lived Assets Disposed of Other Than By Sale [Member]
Assets, Fair Value Disclosure [Abstract]
Assets, fair value	0	0	0	0
Fair Value, Measurements, Nonrecurring [Member] \| Fair Value [Member] \| Level 3 [Member] \| Long-lived Assets Held and Used [Member]
Assets, Fair Value Disclosure [Abstract]
Assets, fair value	6.3		6.3
Fair Value, Measurements, Nonrecurring [Member] \| Fair Value [Member] \| Level 3 [Member] \| Long-lived Assets Disposed of By Sale [Member]
Assets, Fair Value Disclosure [Abstract]
Assets, fair value	0.8	0	0.8	0
NGL Pipelines and Services [Member]
Assets, Fair Value Disclosure [Abstract]
Non-cash asset impairment charges	8.7	2.9	9.7	8.0
Onshore Crude Oil Pipelines and Services [Member]
Assets, Fair Value Disclosure [Abstract]
Non-cash asset impairment charges	16.6	6.2	16.6	6.2
Petrochemical and Refined Products Services [Member]
Assets, Fair Value Disclosure [Abstract]
Non-cash asset impairment charges	$ 1.8	$ 0	$ 11.8	$ 0.3