PENSION AND POST-RETIREMENT BENEFITS - Aggregate Reconciliation of Projected Benefit Obligations, Plan Assets, Funded Status and Amounts Recognized (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Change in Benefit Obligation:
Benefit obligation - beginning of year	$ (629.7)
Benefit obligation - end of year	(666.5)	$ (629.7)
Change in Plan Assets:
Fair value of plan assets - beginning of year	462.4
Fair value of plan assets - end of year	463.0	462.4
Pension Plans
Change in Benefit Obligation:
Benefit obligation - beginning of year	(629.7)	(591.0)
Service cost	(1.7)	(1.9)
Interest cost	(15.0)	(20.0)
Actuarial (loss) gain	(65.8)	(59.3)
Settlement and Curtailment gain	5.5	0.0
Benefits paid	44.0	43.6
Plan Amendments	0.2	(1.2)
Plan participant contributions	(0.5)	(0.6)
Foreign currency translation adjustments	(3.5)	0.7
Benefit obligation - end of year	(666.5)	(629.7)
Change in Plan Assets:
Fair value of plan assets - beginning of year	462.4	432.4
Actual return (loss) on plan assets	35.9	61.3
Employer contributions	9.1	11.4
Settlement gain	(4.1)	0.0
Benefits paid	(44.0)	(43.6)
Plan participant contributions	0.5	0.6
Foreign currency translation adjustments	3.2	0.3
Fair value of plan assets - end of year	463.0	462.4
Total liability	(203.5)	(167.3)
Other Post-Retirement Benefit Plans
Change in Benefit Obligation:
Benefit obligation - beginning of year	(13.4)	(12.2)
Service cost	0.0	0.0
Interest cost	(0.3)	(0.4)
Actuarial (loss) gain	(1.5)	(1.5)
Settlement and Curtailment gain	0.0	0.0
Benefits paid	0.7	0.7
Plan Amendments	0.0	0.0
Plan participant contributions	0.0	0.0
Foreign currency translation adjustments	0.0	0.0
Benefit obligation - end of year	(14.5)	(13.4)
Change in Plan Assets:
Fair value of plan assets - beginning of year	0.0	0.0
Actual return (loss) on plan assets	0.0	0.0
Employer contributions	0.7	0.7
Settlement gain	0.0	0.0
Benefits paid	(0.7)	(0.7)
Plan participant contributions	0.0	0.0
Foreign currency translation adjustments	0.0	0.0
Fair value of plan assets - end of year	0.0	0.0
Total liability	$ (14.5)	$ (13.4)