EMPLOYEE BENEFIT PLANS (Funds Invested in Equity, Fixed income, and Other Investments and Fair Values of Pension Plan Assets by Asset Category) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure
Target plan asset allocations	100.00%
Plan asset allocations	100.00%	100.00%
Equity securities
Defined Benefit Plan Disclosure
Target plan asset allocations	21.00%
Plan asset allocations	21.00%	26.00%
Fixed income securities
Defined Benefit Plan Disclosure
Target plan asset allocations	75.00%
Plan asset allocations	75.00%	70.00%
Other
Defined Benefit Plan Disclosure
Target plan asset allocations	4.00%
Plan asset allocations	4.00%	4.00%
Pension Benefits
Defined Benefit Plan Disclosure
Fair value of plan assets	$ 140.1	$ 153.3	$ 146.1
Pension Benefits | Domestic equity mutual funds
Defined Benefit Plan Disclosure
Fair value of plan assets	0.0	24.0
Pension Benefits | International equity mutual funds
Defined Benefit Plan Disclosure
Fair value of plan assets	28.9	16.2
Pension Benefits | U.S. treasury and government agency securities
Defined Benefit Plan Disclosure
Fair value of plan assets	20.4	19.2
Pension Benefits | Fixed income mutual funds
Defined Benefit Plan Disclosure
Fair value of plan assets	85.1	87.9
Pension Benefits | Insurance contracts
Defined Benefit Plan Disclosure
Fair value of plan assets	4.9	5.3
Pension Benefits | Cash and equivalents
Defined Benefit Plan Disclosure
Fair value of plan assets	0.8	0.7
Pension Benefits | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure
Fair value of plan assets	114.8	128.8
Pension Benefits | Quoted Prices in Active Markets for Identical Assets (Level 1) | Domestic equity mutual funds
Defined Benefit Plan Disclosure
Fair value of plan assets	0.0	24.0
Pension Benefits | Quoted Prices in Active Markets for Identical Assets (Level 1) | International equity mutual funds
Defined Benefit Plan Disclosure
Fair value of plan assets	28.9	16.2
Pension Benefits | Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. treasury and government agency securities
Defined Benefit Plan Disclosure
Fair value of plan assets	0.0	0.0
Pension Benefits | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fixed income mutual funds
Defined Benefit Plan Disclosure
Fair value of plan assets	85.1	87.9
Pension Benefits | Quoted Prices in Active Markets for Identical Assets (Level 1) | Insurance contracts
Defined Benefit Plan Disclosure
Fair value of plan assets	0.0	0.0
Pension Benefits | Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash and equivalents
Defined Benefit Plan Disclosure
Fair value of plan assets	0.8	0.7
Pension Benefits | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure
Fair value of plan assets	25.3	24.5
Pension Benefits | Significant Other Observable Inputs (Level 2) | Domestic equity mutual funds
Defined Benefit Plan Disclosure
Fair value of plan assets	0.0	0.0
Pension Benefits | Significant Other Observable Inputs (Level 2) | International equity mutual funds
Defined Benefit Plan Disclosure
Fair value of plan assets	0.0	0.0
Pension Benefits | Significant Other Observable Inputs (Level 2) | U.S. treasury and government agency securities
Defined Benefit Plan Disclosure
Fair value of plan assets	20.4	19.2
Pension Benefits | Significant Other Observable Inputs (Level 2) | Fixed income mutual funds
Defined Benefit Plan Disclosure
Fair value of plan assets	0.0	0.0
Pension Benefits | Significant Other Observable Inputs (Level 2) | Insurance contracts
Defined Benefit Plan Disclosure
Fair value of plan assets	4.9	5.3
Pension Benefits | Significant Other Observable Inputs (Level 2) | Cash and equivalents
Defined Benefit Plan Disclosure
Fair value of plan assets	0.0	0.0
Pension Benefits | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure
Fair value of plan assets	0.0	0.0
Pension Benefits | Significant Unobservable Inputs (Level 3) | Domestic equity mutual funds
Defined Benefit Plan Disclosure
Fair value of plan assets	0.0	0.0
Pension Benefits | Significant Unobservable Inputs (Level 3) | International equity mutual funds
Defined Benefit Plan Disclosure
Fair value of plan assets	0.0	0.0
Pension Benefits | Significant Unobservable Inputs (Level 3) | U.S. treasury and government agency securities
Defined Benefit Plan Disclosure
Fair value of plan assets	0.0	0.0
Pension Benefits | Significant Unobservable Inputs (Level 3) | Fixed income mutual funds
Defined Benefit Plan Disclosure
Fair value of plan assets	0.0	0.0
Pension Benefits | Significant Unobservable Inputs (Level 3) | Insurance contracts
Defined Benefit Plan Disclosure
Fair value of plan assets	0.0	0.0
Pension Benefits | Significant Unobservable Inputs (Level 3) | Cash and equivalents
Defined Benefit Plan Disclosure
Fair value of plan assets	$ 0.0	$ 0.0