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PENSIONS AND OTHER POSTRETIREMENT BENEFITS (Fair Values of Pension Plan Assets) (Details) - USD ($) $ in Millions | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Reserve For Investment Commitments | $ 48.1 |  |
Fair value of plan assets | 193.4 | $ 188.1 | $ 169.8
Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 700.6 | 749.8 | 712.5
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 | 150.5 | 168.4 |
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 | 40.6 | 45.9 |
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 | 116.8 | 127.7 |
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 | 194.2 | 214.9 |
Hedge Funds [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 40.7 | 41.5 | 38.8
Hedge Funds [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 40.7 | 41.5 |
Private Equity Funds [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 33.1 | 31.2 | 29.1
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 | 33.1 | 31.2 |
Structured Finance [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | $ 62.1 | 65.4 | 61.0
Redemption Request Notice Period | 90 days |  |
Structured Finance [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | $ 62.1 | 65.4 |
Real Estate [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | $ 57.5 | 50.0 | $ 40.9
Redemption Request Notice Period | 45 days |  |
Real Estate [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | $ 57.5 | 50.0 |
Cash [Member] | Pension Benefits [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Fair value of plan assets | 5.1 | 4.8 |
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 | 479.3 | 529.9 |
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 | 150.5 | 168.4 |
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 | 40.6 | 45.9 |
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 | 116.8 | 127.7 |
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 | 166.3 | 183.1 |
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 | 5.1 | 4.8 |
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 | 27.9 | 31.8 |
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 | 27.9 | 31.8 |
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 | 193.4 | 188.1 |
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 | 40.7 | 41.5 |
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 | 33.1 | 31.2 |
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 | 62.1 | 65.4 |
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 | 57.5 | 50.0 |
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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