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DERIVATIVE INSTRUMENTS (Schedule Of Derivatives Not Designated As Hedging Instruments) (Details) - USD ($) $ in Millions | 3 Months Ended
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Mar. 31, 2017 | Mar. 31, 2016
Derivative Instruments, Gain (Loss) [Line Items] |  |
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net | $ 32.2 | $ (1.6)
Commodity Contract [Member] | Other Nonoperating Income (Expense) [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net | (1.3) | 0.0
Customer Supply Agreements [Member] | Product Revenues [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net | 17.8 | (0.1)
Provisional Pricing Arrangements [Member] | Product Revenues [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net | $ 15.7 | $ (1.5)

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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/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624171-113959 + Details
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