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Supplemental Financial Information (Narrative) (Details) - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Supplemental Financial Information [Abstract] |  |  |
Capitalized interest | $ 1.3 | $ 20.9 | $ 62.6
Capital expenditure accruals | $ 5.4 | $ 16.3 | $ 27.8

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- Definition Amount of interest capitalized during the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6450988&loc=d3e26243-108391 + Details
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- Definition Capital expenditure accruals. + References No definition available. + Details
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Balance Type: | debit
Period Type: | duration

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- Definition Supplemental Financial Information [Abstract] + References No definition available. + Details
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