PENSION AND POST-RETIREMENT PLANS - COMPONENTS OF NET PERIODIC BENEFIT COST (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income, net of tax:
Total recognized in other comprehensive (income) loss	$ 0.8	$ 0.8
Pension Benefits
Components of net periodic benefit cost (credit):
Service cost	1.1	0.9
Interest cost	2.6	2.4
Expected return on plan assets	(4.4)	(3.8)
Amortization of net actuarial loss (gain)		0.1
Net periodic benefit credit	(0.7)	(0.4)
Post-retirement benefits
Components of net periodic benefit cost (credit):
Service cost		0.1
Interest cost	0.3	0.3
Amortization of net actuarial loss (gain)	(0.2)	(0.2)
Amortization of prior service credit	(0.9)	(0.9)
Net periodic benefit credit	$ (0.8)	$ (0.7)