Properties and Equipment (Details) (USD $)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Properties and equipment, gross	$ 1,280,479,000us-gaap_PropertyPlantAndEquipmentGross	$ 1,210,913,000us-gaap_PropertyPlantAndEquipmentGross
Less accumulated depreciation	300,000,000	253,099,000
Properties and equipment, net	980,479,000us-gaap_PropertyPlantAndEquipmentNet	957,814,000us-gaap_PropertyPlantAndEquipmentNet
Interest costs, capitalized during period	(1,510,000)us-gaap_InterestCostsCapitalized	(641,000)us-gaap_InterestCostsCapitalized	(277,000)us-gaap_InterestCostsCapitalized
Depreciation	54,700,000us-gaap_Depreciation	58,100,000us-gaap_Depreciation	50,100,000us-gaap_Depreciation
Noncash Project Abandonment Costs	1,900,000	6,200,000	4,800,000
Pipelines and terminals [Member]
Property, Plant and Equipment [Line Items]
Properties and equipment, gross	1,137,157,000	1,077,037,000
Land and right of way [Member]
Property, Plant and Equipment [Line Items]
Properties and equipment, gross	64,458,000	63,425,000
Construction in progress [Member]
Property, Plant and Equipment [Line Items]
Properties and equipment, gross	56,228,000	50,454,000
Property, Plant and Equipment, Other Types [Member]
Property, Plant and Equipment [Line Items]
Properties and equipment, gross	$ 22,636,000	$ 19,997,000

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 50

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

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- Definition

The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

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- Definition

The aggregate amount of write-downs for impairments recognized during the period for long-lived assets held for abandonment, exchange or sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

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- Definition

Amount of interest capitalized during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Allowance for Funds Used during Construction

-URI http://asc.fasb.org/extlink&oid=6504829

Reference 2: http://www.xbrl.org/2003/role/presentationRef

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-Name Accounting Standards Codification

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- Definition

Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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