Asset Retirement Obligations (Details) (USD $)	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012
Asset Retirement Obligation [Abstract]
Asset retirement obligation at January 1	$ 100,637,000	$ 37,693,000
Accretion of discount	5,643,000	2,394,000
Obligations incurred	22,241,000	23,327,000
Obligations settled/removed	(2,341,000)	(8,804,000)
Revisions of estimates	7,366,000	46,027,000
Current liability	5,549,000	4,091,000
Long-term liability	127,997,000	96,546,000
Asset retirement obligation at December 31	133,546,000	100,637,000
Asset retirement obligation period increase due to correction		$ 39,000,000

Accretion of discount relating to Asset Retirement Obligations.

No definition available.

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- Definition

The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 410

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Asset Retirement Obligation

-URI http://asc.fasb.org/extlink&oid=6505190

+ Details

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- Details

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- Definition

Current portion of the carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

+ References

+ Details

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- Definition

Amount of asset retirement obligations incurred during the period.

+ References

+ Details

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- Definition

Amount of asset retirement obligations settled, or otherwise disposed of, during the period. This may include asset retirement obligations transferred to third parties associated with the sale of a long-lived asset.

+ References

+ Details

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- Definition

Net Increase or Decrease in the asset retirement obligation during the period.

+ References

+ Details

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- Definition

Amount of the Increase or Decrease in the amount of the asset retirement obligation during the current period for changes in the amount or timing of the estimated cash flows associated with the settlement of the obligation.

+ References

+ Details

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- Definition

Noncurrent portion of the carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

+ References

+ Details

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