RETIREMENT BENEFIT PLANS - Fair Value of Pension Plan Assets (Details) - Pension Plan - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 53.1	$ 44.0
Total assets at fair value	204.4	188.6
Quoted Prices in Active Market (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8.4	5.7
Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	44.7	38.3
Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Cash and equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8.4	5.7
Cash and equivalents | Quoted Prices in Active Market (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8.4	5.7
Cash and equivalents | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Cash and equivalents | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	19.4	18.4
Mutual funds | Quoted Prices in Active Market (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Mutual funds | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	19.4	18.4
Mutual funds | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Mutual funds | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure [Line Items]
Investments measured at NAV	111.8	98.6
Insurance contracts
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	25.3	19.9
Insurance contracts | Quoted Prices in Active Market (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Insurance contracts | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	25.3	19.9
Insurance contracts | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Other private investments | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure [Line Items]
Investments measured at NAV	$ 39.5	$ 46.0