INCOME TAXES - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Taxes [Line Items]
Estimated effect on income taxes payable if permanently reinvested foreign earnings were repatriated	$ 2.0
Payroll tax deferral, CARES Act	28.5
Payroll tax credit, CARES Act	0.7
Unrecognized tax benefits and related interest and penalties, all of which would affect our effective tax rate if recognized	42.3
Expected decrease in unrecognized tax benefits in next twelve months due to lapsing statutes	1.8
Interest and penalties recognized	1.0	$ 1.0	$ 1.0
Interest and penalties accrued	6.1	6.0
Foreign net operating loss carryforwards tax effect	11.0	11.1
Foreign operating loss carryforwards
Income Taxes [Line Items]
Valuation allowance against deferred tax asset	$ 7.6	$ 8.5