ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Changes in accumulated other comprehensive income (loss) by component, net of taxes
Balance at the beginning of the period	$ 961.2	$ 805.7	$ 755.3
Amortization of prior service cost	(4.6)	(4.7)	(4.5)
Amortization of net loss (gain)	25.0	(9.4)	2.7
Other adjustments	(0.5)	0.2	(0.6)
Balance at the end of the period	1,667.4	961.2	805.7
Comprehensive Income (Loss):
Tax benefit (expense) on other comprehensive income (loss)	(8.1)	4.2	(0.3)
Pensions
Changes in accumulated other comprehensive income (loss) by component, net of taxes
Balance at the beginning of the period	(61.7)	(51.9)
Amortization of prior service cost	(1.7)	(1.8)
Amortization of net loss (gain)	24.3	(8.0)
Balance at the end of the period	(39.1)	(61.7)	(51.9)
Post Retirement
Changes in accumulated other comprehensive income (loss) by component, net of taxes
Balance at the beginning of the period	12.2	16.3
Amortization of prior service cost	(2.8)	(2.8)
Amortization of net loss (gain)	0.7	(1.3)
Balance at the end of the period	10.1	12.2	16.3
Non-Qualified Plans
Changes in accumulated other comprehensive income (loss) by component, net of taxes
Balance at the beginning of the period	(0.6)	(0.4)
Amortization of prior service cost	(0.1)	(0.1)
Amortization of net loss (gain)		(0.1)
Balance at the end of the period	(0.7)	(0.6)	(0.4)
Other
Changes in accumulated other comprehensive income (loss) by component, net of taxes
Balance at the beginning of the period	(0.7)	(0.9)
Foreign currency exchange	(0.9)	0.5
Other adjustments	0.4	(0.3)
Balance at the end of the period	(1.2)	(0.7)	(0.9)
Accumulated Other Comprehensive Income (Loss)
Changes in accumulated other comprehensive income (loss) by component, net of taxes
Balance at the beginning of the period	(50.8)	(36.9)	(34.5)
Amortization of prior service cost	(4.6)	(4.7)
Amortization of net loss (gain)	25.0	(9.4)
Foreign currency exchange	(0.9)	0.5
Other adjustments	0.4	(0.3)
Balance at the end of the period	$ (30.9)	$ (50.8)	$ (36.9)