BENEFIT PLANS - Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
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| Pension Benefits | |||
| Defined Benefit Plan Disclosure [Line Items] | |||
| Service cost | $ 2.8 | $ 3.6 | $ 4.0 |
| Interest cost | 28.3 | 26.4 | 28.5 |
| Expected return on plan assets | (36.2) | (37.5) | (37.4) |
| Amortization of prior service cost | 0.5 | 0.5 | 0.6 |
| Recognized actuarial loss (gain) | 15.2 | 19.7 | 15.5 |
| Total net periodic benefit cost (income) | 10.6 | 12.7 | 11.2 |
| Other Benefits | |||
| Defined Benefit Plan Disclosure [Line Items] | |||
| Service cost | 0.3 | 0.4 | 0.4 |
| Interest cost | 0.9 | 0.8 | 0.9 |
| Expected return on plan assets | (0.9) | (1.1) | (1.2) |
| Amortization of prior service cost | (1.0) | (1.0) | (1.0) |
| Recognized actuarial loss (gain) | 1.3 | 1.4 | 1.3 |
| Total net periodic benefit cost (income) | $ 0.6 | $ 0.5 | $ 0.4 |
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- Definition Amount of gain (loss) recognized in net periodic benefit (cost) credit of defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of prior service cost (credit) recognized in net periodic benefit cost (credit) of defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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- Definition Amount of expected return (loss) recognized in net periodic benefit (cost) credit, calculated based on expected long-term rate of return and market-related value of plan assets of defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of cost recognized for passage of time related to defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of net periodic benefit cost (credit) for defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of cost for actuarial present value of benefits attributed to service rendered by employee for defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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