Asset Retirement Obligations (Details) (USD $) In Millions | 9 Months Ended |
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Sep. 30, 2011 | |
Asset retirement obligations: | |
Asset retirement obligations | $ 28.0 |
Increase (decrease) from prior year end | $ (6.6) |
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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. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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- Definition Net Increase or Decrease in the asset retirement obligation during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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