RETIREMENT BENEFIT PLANS - Components of Net Periodic Benefit Cost (Details) - Retirement Plans - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 0.2	$ 0.0	$ 0.6
Interest cost	14.0	8.8	8.9
Expected return on plan assets	(14.7)	(13.5)	(16.8)
Amortization of prior service cost/(credit)	0.5	0.2	0.2
Amortization of net actuarial (gain)/loss	3.8	0.8	2.7
Settlement	0.0	0.0	4.4
Curtailment (gain)/loss	0.0	0.0	(0.3)
Net periodic benefit cost/(credit)	$ 3.8	$ (3.7)	$ (0.3)