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PENSIONS AND OTHER POSTRETIREMENT BENEFITS (Fair Values of Pension Plan Assets) (Details) - USD ($) $ in Millions | Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014
--- | --- | --- | ---
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | $ 202.4 | $ 193.4 | $ 188.1
Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 685.8 | 700.6 | 749.8
Equity Securities [Member] | U S Large Cap [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 144.7 | 150.5 |
Equity Securities [Member] | U S Small Mid Cap [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 39.9 | 40.6 |
Equity Securities [Member] | International [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 111.8 | 116.8 |
Fixed Income Investments [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 181.2 | 194.2 |
Hedge Funds [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 40.6 | 40.7 | 41.5
Hedge Funds [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 40.6 | 40.7 |
Private Equity Funds [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 36.1 | 33.1 | 31.2
Private Equity Funds [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 36.1 | 33.1 |
Structured Finance [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 63.8 | 62.1 | 65.4
Structured Finance [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 63.8 | 62.1 |
Real Estate [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 61.9 | 57.5 | $ 50.0
Real Estate [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 61.9 | 57.5 |
Cash [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 5.8 | 5.1 |
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 459.7 | 479.3 |
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Equity Securities [Member] | U S Large Cap [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 144.7 | 150.5 |
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Equity Securities [Member] | U S Small Mid Cap [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 39.9 | 40.6 |
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Equity Securities [Member] | International [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 111.8 | 116.8 |
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Fixed Income Investments [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 157.5 | 166.3 |
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Hedge Funds [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 0.0 | 0.0 |
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Private Equity Funds [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 0.0 | 0.0 |
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Structured Finance [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 0.0 | 0.0 |
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Real Estate [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 0.0 | 0.0 |
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Cash [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 5.8 | 5.1 |
Fair Value, Inputs, Level 2 [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 23.7 | 27.9 |
Fair Value, Inputs, Level 2 [Member] | Equity Securities [Member] | U S Large Cap [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 0.0 | 0.0 |
Fair Value, Inputs, Level 2 [Member] | Equity Securities [Member] | U S Small Mid Cap [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 0.0 | 0.0 |
Fair Value, Inputs, Level 2 [Member] | Equity Securities [Member] | International [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 0.0 | 0.0 |
Fair Value, Inputs, Level 2 [Member] | Fixed Income Investments [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 23.7 | 27.9 |
Fair Value, Inputs, Level 2 [Member] | Hedge Funds [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 0.0 | 0.0 |
Fair Value, Inputs, Level 2 [Member] | Private Equity Funds [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 0.0 | 0.0 |
Fair Value, Inputs, Level 2 [Member] | Structured Finance [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 0.0 | 0.0 |
Fair Value, Inputs, Level 2 [Member] | Real Estate [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 0.0 | 0.0 |
Fair Value, Inputs, Level 2 [Member] | Cash [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 0.0 | 0.0 |
Significant Unobservable Inputs (Level 3) [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 202.4 | 193.4 |
Significant Unobservable Inputs (Level 3) [Member] | Equity Securities [Member] | U S Large Cap [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 0.0 | 0.0 |
Significant Unobservable Inputs (Level 3) [Member] | Equity Securities [Member] | U S Small Mid Cap [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 0.0 | 0.0 |
Significant Unobservable Inputs (Level 3) [Member] | Equity Securities [Member] | International [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 0.0 | 0.0 |
Significant Unobservable Inputs (Level 3) [Member] | Fixed Income Investments [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 0.0 | 0.0 |
Significant Unobservable Inputs (Level 3) [Member] | Hedge Funds [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 40.6 | 40.7 |
Significant Unobservable Inputs (Level 3) [Member] | Private Equity Funds [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 36.1 | 33.1 |
Significant Unobservable Inputs (Level 3) [Member] | Structured Finance [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 63.8 | 62.1 |
Significant Unobservable Inputs (Level 3) [Member] | Real Estate [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 61.9 | 57.5 |
Significant Unobservable Inputs (Level 3) [Member] | Cash [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | $ 0.0 | $ 0.0 |

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