Quarterly report pursuant to Section 13 or 15(d)

DERIVATIVE INSTRUMENTS (Schedule Of Derivative Instruments In Statement Of Financial Position, Fair Value) (Details)

v3.20.1
DERIVATIVE INSTRUMENTS (Schedule Of Derivative Instruments In Statement Of Financial Position, Fair Value) (Details) - USD ($)
$ in Millions
Mar. 31, 2020
Dec. 31, 2019
Commodity Contract [Member] | Derivative Asset [Member]    
Derivatives, Fair Value [Line Items]    
Derivative Asset $ 1.6  
Commodity Contract [Member] | Other Current Liabilities [Member]    
Derivatives, Fair Value [Line Items]    
Derivative liability 26.5 $ 3.2
Commodity Contract [Member] | Other Noncurrent Liabilities [Member]    
Derivatives, Fair Value [Line Items]    
Derivative liability 3.4  
Foreign Exchange Contract [Member] | Other Current Liabilities [Member]    
Derivatives, Fair Value [Line Items]    
Derivative liability 1.6  
Foreign Exchange Contract [Member] | Other Noncurrent Liabilities [Member]    
Derivatives, Fair Value [Line Items]    
Derivative liability 0.9  
Customer Supply Agreement [Member] | Derivative Asset [Member]    
Derivatives, Fair Value [Line Items]    
Derivative Asset 19.0 44.5
Provisional Pricing Arrangements [Member] | Derivative Asset [Member]    
Derivatives, Fair Value [Line Items]    
Derivative Asset 0.6 1.3
Provisional Pricing Arrangements [Member] | Other Current Liabilities [Member]    
Derivatives, Fair Value [Line Items]    
Derivative liability   1.1
Fair Value, Inputs, Level 2 [Member] | Commodity Contract [Member] | Derivative Asset [Member]    
Derivatives, Fair Value [Line Items]    
Derivative Asset 1.6  
Fair Value, Inputs, Level 2 [Member] | Commodity Contract [Member] | Other Current Liabilities [Member]    
Derivatives, Fair Value [Line Items]    
Derivative liability 26.5 3.2
Fair Value, Inputs, Level 2 [Member] | Commodity Contract [Member] | Other Noncurrent Liabilities [Member]    
Derivatives, Fair Value [Line Items]    
Derivative liability 3.4  
Fair Value, Inputs, Level 2 [Member] | Foreign Exchange Contract [Member] | Other Current Liabilities [Member]    
Derivatives, Fair Value [Line Items]    
Derivative liability 1.6  
Fair Value, Inputs, Level 2 [Member] | Foreign Exchange Contract [Member] | Other Noncurrent Liabilities [Member]    
Derivatives, Fair Value [Line Items]    
Derivative liability 0.9  
Fair Value, Inputs, Level 2 [Member] | Customer Supply Agreement [Member] | Derivative Asset [Member]    
Derivatives, Fair Value [Line Items]    
Derivative Asset   0.0
Fair Value, Inputs, Level 2 [Member] | Provisional Pricing Arrangements [Member] | Derivative Asset [Member]    
Derivatives, Fair Value [Line Items]    
Derivative Asset   0.0
Fair Value, Inputs, Level 2 [Member] | Provisional Pricing Arrangements [Member] | Other Current Liabilities [Member]    
Derivatives, Fair Value [Line Items]    
Derivative liability   0.0
Fair Value, Inputs, Level 3 [Member] | Commodity Contract [Member] | Derivative Asset [Member]    
Derivatives, Fair Value [Line Items]    
Derivative Asset 0.0  
Fair Value, Inputs, Level 3 [Member] | Commodity Contract [Member] | Other Current Liabilities [Member]    
Derivatives, Fair Value [Line Items]    
Derivative liability 0.0 0.0
Fair Value, Inputs, Level 3 [Member] | Customer Supply Agreement [Member] | Derivative Asset [Member]    
Derivatives, Fair Value [Line Items]    
Derivative Asset 19.0 44.5
Fair Value, Inputs, Level 3 [Member] | Provisional Pricing Arrangements [Member] | Derivative Asset [Member]    
Derivatives, Fair Value [Line Items]    
Derivative Asset 0.6 1.3
Fair Value, Inputs, Level 3 [Member] | Provisional Pricing Arrangements [Member] | Other Current Liabilities [Member]    
Derivatives, Fair Value [Line Items]    
Derivative liability   1.1
Valuation, Market Approach [Member] | Fair Value, Inputs, Level 2 [Member] | Designated as Hedging Instrument [Member] | Commodity Contract [Member] | Derivative Asset [Member]    
Derivatives, Fair Value [Line Items]    
Derivative Asset 0.3 0.0
Valuation, Market Approach [Member] | Fair Value, Inputs, Level 2 [Member] | Designated as Hedging Instrument [Member] | Commodity Contract [Member] | Other Current Liabilities [Member]    
Derivatives, Fair Value [Line Items]    
Derivative liability (25.9) (3.2)
Valuation, Market Approach [Member] | Fair Value, Inputs, Level 2 [Member] | Designated as Hedging Instrument [Member] | Commodity Contract [Member] | Other Noncurrent Liabilities [Member]    
Derivatives, Fair Value [Line Items]    
Derivative liability (2.8) 0.0
Valuation, Market Approach [Member] | Fair Value, Inputs, Level 2 [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Other Current Liabilities [Member]    
Derivatives, Fair Value [Line Items]    
Derivative liability (1.6) 0.0
Valuation, Market Approach [Member] | Fair Value, Inputs, Level 2 [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Other Noncurrent Liabilities [Member]    
Derivatives, Fair Value [Line Items]    
Derivative liability (0.9) 0.0
Valuation, Market Approach [Member] | Fair Value, Inputs, Level 2 [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contract [Member] | Derivative Asset [Member]    
Derivatives, Fair Value [Line Items]    
Derivative Asset 1.3 0.0
Valuation, Market Approach [Member] | Fair Value, Inputs, Level 2 [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contract [Member] | Other Current Liabilities [Member]    
Derivatives, Fair Value [Line Items]    
Derivative liability (0.6) 0.0
Valuation, Market Approach [Member] | Fair Value, Inputs, Level 2 [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contract [Member] | Other Noncurrent Liabilities [Member]    
Derivatives, Fair Value [Line Items]    
Derivative liability (0.6) 0.0
Valuation, Market Approach [Member] | Fair Value, Inputs, Level 3 [Member] | Not Designated as Hedging Instrument [Member] | Customer Supply Agreement [Member]    
Derivatives, Fair Value [Line Items]    
Derivative Asset 19.0 44.5
Valuation, Market Approach [Member] | Fair Value, Inputs, Level 3 [Member] | Not Designated as Hedging Instrument [Member] | Provisional Pricing Arrangements [Member]    
Derivatives, Fair Value [Line Items]    
Derivative Asset 0.6 1.3
Derivative liability $ 0.0 $ (1.1)