EMPLOYEE BENEFITS - Schedule of Estimated Future Benefit Payments (Details) $ in Millions	Dec. 31, 2020 USD ($)
Pension Plan
Defined Contribution Plan Disclosure [Line Items]
2021	$ 346.9
2022	355.6
2023	362.9
2024	397.5
2025	373.8
2026 - 2030	1,883.2
Other Postretirement Benefits Plan
Defined Contribution Plan Disclosure [Line Items]
2021	60.1
2022	60.1
2023	59.7
2024	59.1
2025	58.3
2026 - 2030	$ 273.6

Amount of benefit for defined benefit plan expected to be paid in five fiscal years after fifth fiscal year following current fiscal year.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920

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Amount of benefit for defined benefit plan expected to be paid in next fiscal year following current fiscal year.

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Amount of benefit for defined benefit plan expected to be paid in second fiscal year following current fiscal year.

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