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FAIR VALUE MEASUREMENTS (Schedule Of Quantitative Inputs And Assumptions For Level 3 Assets And Liabilities) (Details) - USD ($) | 9 Months Ended |
--- | --- | ---
Sep. 30, 2019 | Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | $ 72,800,000 | $ 91,500,000
Derivative liability | 32,600,000 | 3,700,000
Not Designated as Hedging Instrument [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 72,800,000 | 91,400,000
Derivative liability | 30,200,000 | 0
Fair Value, Inputs, Level 3 [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 72,800,000 | 91,400,000
Derivative liability | 30,200,000 | 0
Fair Value, Inputs, Level 3 [Member] | Not Designated as Hedging Instrument [Member] | Valuation, Market Approach [Member] | Customer Supply Agreement [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 71,200,000 | 89,300,000
Fair Value, Inputs, Level 3 [Member] | Not Designated as Hedging Instrument [Member] | Valuation, Market Approach [Member] | Provisional Pricing Arrangements [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative assets | 1,600,000 | 2,100,000
Derivative liability | 30,200,000 |
Derivative Asset [Member] | Fair Value, Inputs, Level 3 [Member] | Not Designated as Hedging Instrument [Member] | Valuation, Market Approach [Member] | Customer Supply Agreement [Member] | Customer's Hot-Rolled Steel Estimate [Member] | Minimum [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value, Measurement With Unobservable Inputs Range | 631 |
Derivative Asset [Member] | Fair Value, Inputs, Level 3 [Member] | Not Designated as Hedging Instrument [Member] | Valuation, Market Approach [Member] | Customer Supply Agreement [Member] | Customer's Hot-Rolled Steel Estimate [Member] | Weighted Average [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value, Measurement With Unobservable Inputs Range | 633 |
Derivative Asset [Member] | Fair Value, Inputs, Level 3 [Member] | Not Designated as Hedging Instrument [Member] | Valuation, Market Approach [Member] | Customer Supply Agreement [Member] | Customer's Hot-Rolled Steel Estimate [Member] | Maximum [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value, Measurement With Unobservable Inputs Range | 700 |
Derivative Asset [Member] | Fair Value, Inputs, Level 3 [Member] | Not Designated as Hedging Instrument [Member] | Valuation, Market Approach [Member] | Provisional Pricing Arrangements [Member] | Managements Estimate Of 62% Fee [Member] | Weighted Average [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value, Measurement With Unobservable Inputs Range | 100 |
Derivative Liability [Member] | Fair Value, Inputs, Level 3 [Member] | Not Designated as Hedging Instrument [Member] | Valuation, Market Approach [Member] | Provisional Pricing Arrangements [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative liability |  | $ 0
Derivative Liability [Member] | Fair Value, Inputs, Level 3 [Member] | Not Designated as Hedging Instrument [Member] | Valuation, Market Approach [Member] | Provisional Pricing Arrangements [Member] | Managements Estimate Of 62% Fee [Member] | Minimum [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value, Measurement With Unobservable Inputs Range | 87 |
Derivative Liability [Member] | Fair Value, Inputs, Level 3 [Member] | Not Designated as Hedging Instrument [Member] | Valuation, Market Approach [Member] | Provisional Pricing Arrangements [Member] | Managements Estimate Of 62% Fee [Member] | Weighted Average [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value, Measurement With Unobservable Inputs Range | 96 |
Derivative Liability [Member] | Fair Value, Inputs, Level 3 [Member] | Not Designated as Hedging Instrument [Member] | Valuation, Market Approach [Member] | Provisional Pricing Arrangements [Member] | Managements Estimate Of 62% Fee [Member] | Maximum [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value, Measurement With Unobservable Inputs Range | 100 |
Derivative Liability [Member] | Fair Value, Inputs, Level 3 [Member] | Not Designated as Hedging Instrument [Member] | Valuation, Market Approach [Member] | Provisional Pricing Arrangements [Member] | PPI Estimates [Member] | Minimum [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value, Measurement With Unobservable Inputs Range | 172 |
Derivative Liability [Member] | Fair Value, Inputs, Level 3 [Member] | Not Designated as Hedging Instrument [Member] | Valuation, Market Approach [Member] | Provisional Pricing Arrangements [Member] | PPI Estimates [Member] | Maximum [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value, Measurement With Unobservable Inputs Range | 214 |
Derivative Liability [Member] | Fair Value, Inputs, Level 3 [Member] | Not Designated as Hedging Instrument [Member] | Valuation, Market Approach [Member] | Provisional Pricing Arrangements [Member] | Atlantic Basin Pellet Premium [Member] | Weighted Average [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value, Measurement With Unobservable Inputs Range | 59 |
Derivative Liability [Member] | Fair Value, Inputs, Level 3 [Member] | Not Designated as Hedging Instrument [Member] | Valuation, Market Approach [Member] | PPI Estimates [Member] | Managements Estimate Of 62% Fee [Member] | Weighted Average [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value, Measurement With Unobservable Inputs Range | $ 198 |

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