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Income Taxes Reconciliation of Unrecognized Tax Benefits (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended | 12 Months Ended |
--- | --- | --- | --- | ---
Apr. 01, 2017 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014
Predecessor |  |  |  |  |
Reconciliation of Unrecognized Tax Benefits [Line Items] |  |  |  |  |
Unrecognized Tax Benefits | $ 12.5 |  | $ 20.1 | $ 22.9 | $ 44.5
Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions | 0.0 |  | 1.5 | 2.3 |
Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions | (7.6) |  | (2.8) | (23.5) |
Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities | 0.0 |  | $ (1.5) | $ (0.4) |
Successor |  |  |  |  |
Reconciliation of Unrecognized Tax Benefits [Line Items] |  |  |  |  |
Unrecognized Tax Benefits | $ 12.5 | $ 12.7 |  |  |
Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions |  | 0.8 |  |  |
Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions |  | (0.5) |  |  |
Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities |  | $ (0.1) |  |  |

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- Definition [Line Items] for Reconciliation of Unrecognized Tax Benefits [Table] + References No definition available. + Details
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- Definition Amount of unrecognized tax benefits. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15A -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319 + Details
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- Definition Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15A -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319 + Details
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- Definition Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15A -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319 + Details
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- Definition Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15A -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319 + Details
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