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Property, Plant and Equipment Property, Plant and Equipment - Additional Information (Details) - USD ($) $ in Millions | Mar. 31, 2017 | Dec. 31, 2016
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Property, Plant and Equipment [Abstract] |  |
Asset retirement costs | $ 43.0 | $ 42.9

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- Definition The amount of asset retirement costs previously incurred and capitalized separately from the capitalized amount of the associated long-lived assets. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e61901-109447 + Details
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- References No definition available. + Details
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