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PENSIONS AND OTHER POSTRETIREMENT BENEFITS (Contributions) (Details) $ in Millions | 12 Months Ended
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Dec. 31, 2019 USD ($) | Dec. 31, 2018 USD ($)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Employer contributions | $ 3.7 | $ 3.8
Expected employer contributions, next fiscal year | $ 3.5 |
Defined Benefit Plan, Funded Percentage | 70.00% |
Value of VEBA Trust Assets as a Percentage of the Funding Obligation | 0.9 |
Pension Plan [Member] |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Employer contributions | $ 16.4 | 27.6
Expected employer contributions, next fiscal year | 20.2 |
Other Postretirement Benefits Plan [Member] |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Employer contributions | 2.5 | 3.0
Direct Payments [Member] |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Employer contributions | 3.7 | 3.8
Expected employer contributions, next fiscal year | 3.5 |
Veba Trust [Member] |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Employer contributions | 0.0 | $ 0.0
Expected employer contributions, next fiscal year | $ 0.0 |

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