Accounting Policies (Details) (USD $)	6 Months Ended
Jun. 30, 2013	Dec. 31, 2012
Restricted Cash
Current restricted cash	$ 19,376,000	$ 21,341,000
Long-term restricted cash	29,884,000	29,884,000
Inventories
Materials and supplies inventory	32,400,000	33,100,000
Hydrocarbons inventory	21,100,000	200,000
Restricted Cash \| Commercial Debt Facility
Restricted Cash
Restricted cash period required as per commercial debt facility to meet interest and commitment fee payments	6 months
Current restricted cash	19,400,000	21,300,000
Restricted Cash \| Petroleum agreements - performance guarantees
Restricted Cash
Long-term restricted cash	$ 29,900,000	$ 29,900,000

Period of time used to determine level of contractually required restricted cash balances.

No definition available.

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- Definition

Carrying amount as of the balance sheet date of petroleum or crude oil.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.6(a))

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-Publisher SEC

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-Number 210

-Section 02

-Paragraph 6

-Subparagraph a

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- Definition

Carrying amount, net of valuation reserves and adjustments, as of the balance sheet date of products used directly or indirectly in the manufacturing or production process, which may or may not become part of the final product. May also include items used in the storage, presentation or transportation of physical goods.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 330

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SAB TOPIC 5.BB)

-URI http://asc.fasb.org/extlink&oid=6386940&loc=d3e100047-122729

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-Publisher FASB

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-Topic 210

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-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.6(a)(5))

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- Definition

The carrying amounts of cash and cash equivalent items which are restricted as to withdrawal or usage. Restrictions may include legally restricted deposits held as compensating balances against short-term borrowing arrangements, contracts entered into with others, or entity statements of intention with regard to particular deposits; however, time deposits and short-term certificates of deposit are not generally included in legally restricted deposits. Excludes compensating balance arrangements that are not agreements which legally restrict the use of cash amounts shown on the balance sheet. For a classified balance sheet represents the current portion only (the noncurrent portion has a separate concept); there is a separate and distinct element for unclassified presentations.

+ References

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

-Publisher AICPA

-Name Audit and Accounting Guide (AAG)

-Number AAG-BRD

-Paragraph 80

-Subparagraph Exhibit 4-8, 3

-IssueDate 2006-05-01

-Chapter 4

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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- Definition

Cash and equivalents whose use in whole or in part is restricted for the long-term, generally by contractual agreements or regulatory requirements.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

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