PENSION AND POST-RETIREMENT BENEFITS - Fair Value of Asset Categories (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	$ 474.0	$ 463.0
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	474.0	463.0	$ 462.4
Pension Plans | Total
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	454.3	387.9
Pension Plans | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	235.0	189.7
Pension Plans | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	219.3	198.2
Pension Plans | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.0	0.0
Pension Plans | Investments measured at Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	19.7	75.1
Pension Plans | Mutual Funds, Corporate Bonds | Total
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	21.9	10.8
Pension Plans | Mutual Funds, Corporate Bonds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	21.9	10.8
Pension Plans | Mutual Funds, Corporate Bonds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.0	0.0
Pension Plans | Mutual Funds, Corporate Bonds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.0	0.0
Pension Plans | Mutual Funds, Government Bonds | Total
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	25.4	15.8
Pension Plans | Mutual Funds, Government Bonds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	25.4	15.8
Pension Plans | Mutual Funds, Government Bonds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.0	0.0
Pension Plans | Mutual Funds, Government Bonds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.0	0.0
Pension Plans | Mutual Funds, U.S. Large Cap Equiy | Total
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.7	0.0
Pension Plans | Mutual Funds, U.S. Large Cap Equiy | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.7	0.0
Pension Plans | Mutual Funds, U.S. Large Cap Equiy | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.0	0.0
Pension Plans | Mutual Funds, U.S. Large Cap Equiy | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.0	0.0
Pension Plans | Mutual Funds, International Equities | Total
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	15.8	21.7
Pension Plans | Mutual Funds, International Equities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	15.8	21.7
Pension Plans | Mutual Funds, International Equities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.0	0.0
Pension Plans | Mutual Funds, International Equities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.0	0.0
Pension Plans | Mutual Funds, Emerging Markets International Equity | Total
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	2.8	1.7
Pension Plans | Mutual Funds, Emerging Markets International Equity | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	2.8	1.7
Pension Plans | Mutual Funds, Emerging Markets International Equity | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.0	0.0
Pension Plans | Mutual Funds, Emerging Markets International Equity | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.0	0.0
Pension Plans | Mutual Funds, U.S., Small/Mid Cap Equity | Total
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.6	1.1
Pension Plans | Mutual Funds, U.S., Small/Mid Cap Equity | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.6	1.1
Pension Plans | Mutual Funds, U.S., Small/Mid Cap Equity | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.0
Pension Plans | Mutual Funds, U.S., Small/Mid Cap Equity | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.0
Pension Plans | Mutual Funds, Cash and Cash Equivalents | Total
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.3	6.0
Pension Plans | Mutual Funds, Cash and Cash Equivalents | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.3	6.0
Pension Plans | Mutual Funds, Cash and Cash Equivalents | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.0	0.0
Pension Plans | Mutual Funds, Cash and Cash Equivalents | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.0	0.0
Pension Plans | Mutual Funds, Other | Total
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	1.2	1.2
Pension Plans | Mutual Funds, Other | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	1.2	1.2
Pension Plans | Mutual Funds, Other | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.0	0.0
Pension Plans | Mutual Funds, Other | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.0	0.0
Pension Plans | Fixed Income Securities, Government Bonds | Total
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	85.9	68.1
Pension Plans | Fixed Income Securities, Government Bonds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.0	0.0
Pension Plans | Fixed Income Securities, Government Bonds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	85.9	68.1
Pension Plans | Fixed Income Securities, Government Bonds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.0	0.0
Pension Plans | Common and Collective Funds, Corporate Bonds | Total
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	27.5	34.6
Pension Plans | Common and Collective Funds, Corporate Bonds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	15.8	20.7
Pension Plans | Common and Collective Funds, Corporate Bonds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	11.7	13.9
Pension Plans | Common and Collective Funds, Corporate Bonds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.0	0.0
Pension Plans | Common and Collective Funds, Government Bonds | Total
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	42.1	38.7
Pension Plans | Common and Collective Funds, Government Bonds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	5.1	4.8
Pension Plans | Common and Collective Funds, Government Bonds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	37.0	33.9
Pension Plans | Common and Collective Funds, Government Bonds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.0	0.0
Pension Plans | Common and Collective Funds, U.S. Large Cap Equity | Total
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	98.4	59.0
Pension Plans | Common and Collective Funds, U.S. Large Cap Equity | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	91.9	51.0
Pension Plans | Common and Collective Funds, U.S. Large Cap Equity | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	6.5	8.0
Pension Plans | Common and Collective Funds, U.S. Large Cap Equity | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.0	0.0
Pension Plans | Common and Collective Funds, U.S. Small/Mid Cap Equity | Total
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	19.4	24.6
Pension Plans | Common and Collective Funds, U.S. Small/Mid Cap Equity | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	19.4	24.6
Pension Plans | Common and Collective Funds, U.S. Small/Mid Cap Equity | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.0	0.0
Pension Plans | Common and Collective Funds, U.S. Small/Mid Cap Equity | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.0	0.0
Pension Plans | Common and Collective Funds, International Equities | Total
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	74.8	72.7
Pension Plans | Common and Collective Funds, International Equities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	3.3	4.4
Pension Plans | Common and Collective Funds, International Equities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	71.5	68.3
Pension Plans | Common and Collective Funds, International Equities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.0	0.0
Pension Plans | Common and Collective Funds, Emerging Markets International Equity | Total
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	27.5	24.5
Pension Plans | Common and Collective Funds, Emerging Markets International Equity | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	20.4	19.1
Pension Plans | Common and Collective Funds, Emerging Markets International Equity | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	7.1	5.4
Pension Plans | Common and Collective Funds, Emerging Markets International Equity | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.0	0.0
Pension Plans | Common and Collective Funds, Cash and Cash Equivalents | Total
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	2.8	1.8
Pension Plans | Common and Collective Funds, Cash and Cash Equivalents | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	2.8	1.8
Pension Plans | Common and Collective Funds, Cash and Cash Equivalents | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.0	0.0
Pension Plans | Common and Collective Funds, Cash and Cash Equivalents | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.0	0.0
Pension Plans | Common and Collective Funds, Other | Total
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	(0.4)	0.6
Pension Plans | Common and Collective Funds, Other | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.0	0.0
Pension Plans | Common and Collective Funds, Other | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	(0.4)	0.6
Pension Plans | Common and Collective Funds, Other | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.0	0.0
Pension Plans | Cash and Cash Equivalents | Total
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	7.6	5.0
Pension Plans | Cash and Cash Equivalents | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	7.6	5.0
Pension Plans | Cash and Cash Equivalents | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.0	0.0
Pension Plans | Cash and Cash Equivalents | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	0.0	0.0
Pension Plans | Common and Collective Funds | Investments measured at Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	19.7	45.9
Pension Plans | Hedge Funds | Investments measured at Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Total Plan Assets at Fair Value	$ 0.0	$ 29.2