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DERIVATIVE INSTRUMENTS (Schedule Of Derivatives Not Designated As Hedging Instruments) (Details) - Not Designated as Hedging Instrument [Member] - USD ($) $ in Millions | 3 Months Ended
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Mar. 31, 2019 | Mar. 31, 2018
Derivative Instruments, Gain (Loss) [Line Items] |  |
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net | $ 5.5 | $ 43.8
Customer Supply Agreement [Member] | Revenue from Contract with Customer [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Amount of gain/(loss) recognized in income on derivative | 17.1 | 41.9
Provisional Pricing Arrangements [Member] | Revenue from Contract with Customer [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Amount of gain/(loss) recognized in income on derivative | $ (11.6) | $ 1.9

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- Definition Amount of increase (decrease) in the fair value of derivatives recognized in the income statement. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5618551-113959 + Details
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- Definition Amount of realized and unrealized gain (loss) of derivative instruments not designated or qualifying as hedging instruments. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4CC -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL109998890-113959 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624171-113959 + Details
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