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DEBT AND CREDIT FACILITIES (Schedule of Extinguishment of Debt) (Details) - USD ($) $ in Millions |  |  | 3 Months Ended
--- | --- | --- | ---
Mar. 27, 2020 | Mar. 13, 2020 | Mar. 31, 2020 | Mar. 31, 2019
Extinguishment of Debt [Line Items] |  |  |  |
Extinguishment of Debt, Amount |  |  | $ 739.9 | $ 10.0
Gain (loss) on extinguishment of debt |  |  | 3.2 | (0.3)
7.625% 2021 AK Senior Notes [Member] |  |  |  |
Extinguishment of Debt [Line Items] |  |  |  |
Extinguishment of Debt, Amount | $ 8.5 | $ 364.2 | 372.7 |
Gain (loss) on extinguishment of debt |  |  | 0.4 |
7.50% 2023 AK Senior Notes [Member] |  |  |  |
Extinguishment of Debt [Line Items] |  |  |  |
Extinguishment of Debt, Amount | $ 56.5 | $ 310.7 | 367.2 |
Gain (loss) on extinguishment of debt |  |  | $ 2.8 |
4.875% 2021 Senior Notes [Member] |  |  |  |
Extinguishment of Debt [Line Items] |  |  |  |
Extinguishment of Debt, Amount |  |  |  | 10.0
Gain (loss) on extinguishment of debt |  |  |  | $ (0.3)

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