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PENSIONS AND POSTRETIREMENT BENEFITS (Fair Value Measurements Using Significant Unobservable Inputs (Level 3) on Changes in Pension Plan Assets) (Details) - Fair Value, Inputs, Level 3 [Member] - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2019 | Dec. 31, 2018
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward] |  |
Fair value of plan assets — beginning of year | $ 229.1 | $ 215.6
Actual return on plan assets: |  |
Relating to assets still held at the reporting date | (1.3) | 12.5
Relating to assets sold during the period | 30.6 | 4.0
Purchases | 16.5 | 5.2
Sales | (59.9) | (8.2)
Other | (2.6) |
Fair value of plan assets — end of year | 212.4 | 229.1
Hedge Funds [Member] |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward] |  |
Fair value of plan assets — beginning of year | 37.2 | 37.4
Actual return on plan assets: |  |
Relating to assets still held at the reporting date | 3.4 | (0.2)
Relating to assets sold during the period | 0.0 | 0.0
Purchases | 0.0 | 0.0
Sales | 0.0 | 0.0
Other | (0.4) |
Fair value of plan assets — end of year | 40.2 | 37.2
Private Equity Funds [Member] |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward] |  |
Fair value of plan assets — beginning of year | 42.6 | 39.8
Actual return on plan assets: |  |
Relating to assets still held at the reporting date | (1.0) | 1.4
Relating to assets sold during the period | 1.2 | 4.0
Purchases | 16.5 | 5.2
Sales | (9.3) | (7.8)
Other | (0.5) |
Fair value of plan assets — end of year | 49.5 | 42.6
Structured Finance [Member] |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward] |  |
Fair value of plan assets — beginning of year | 78.8 | 72.9
Actual return on plan assets: |  |
Relating to assets still held at the reporting date | 0.5 | 5.9
Relating to assets sold during the period | 0.8 | 0.0
Purchases | 0.0 | 0.0
Sales | (26.8) | 0.0
Other | (1.0) |
Fair value of plan assets — end of year | 52.3 | 78.8
Real Estate [Member] |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward] |  |
Fair value of plan assets — beginning of year | 70.5 | 65.5
Actual return on plan assets: |  |
Relating to assets still held at the reporting date | (4.2) | 5.4
Relating to assets sold during the period | 28.6 | 0.0
Purchases | 0.0 | 0.0
Sales | (23.8) | (0.4)
Other | (0.7) |
Fair value of plan assets — end of year | $ 70.4 | $ 70.5

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