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COMMITMENTS AND CONTINGENCIES (Narrative) (Details) - USD ($) $ in Millions | 3 Months Ended |
--- | --- | ---
Mar. 31, 2020 | Dec. 31, 2019
Unrecorded Unconditional Purchase Obligation [Line Items] |  |
Estimated Project Capital Expenditures | $ 1,000.0 |
Total Project Expenditures, Excluding Capitalized Interest | 800.0 |
Environmental obligations accrued | 40.0 | $ 2.0
Hamilton Plant [Member] |  |
Unrecorded Unconditional Purchase Obligation [Line Items] |  |
Environmental obligations accrued | 0.7 |
Ashland Works Coke Plant [Member] |  |
Unrecorded Unconditional Purchase Obligation [Line Items] |  |
Environmental obligations accrued | 1.4 |
Capital Addition Purchase Commitments [Member] |  |
Unrecorded Unconditional Purchase Obligation [Line Items] |  |
Capital Additions, Purchase Commitments | $ 150.0 |

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- Definition Total costs accrued as of the balance sheet date for environmental loss contingencies. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=118942415&loc=d3e14326-108349 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 25 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6395460&loc=d3e13647-108346 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 30 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=6393242&loc=d3e13207-110859 + Details
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