SUPPLEMENTAL GUARANTOR FINANCIAL INFORMATION (Statements of Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Supplemental Guarantor Financial Information Statements Of Comprehensive Income (Loss) [Line Items]
Net income (loss)	$ 41.7	$ 20.9
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments, net	(8.3)	12.4
Unrealized losses on derivative contracts, net	(3.3)	(0.1)
Amortization of prior service costs and actuarial losses, net	5.7	5.4
Total other comprehensive (loss) income, net of tax	(5.9)	17.7
Comprehensive income	35.8	38.6
Parent Guarantor
Supplemental Guarantor Financial Information Statements Of Comprehensive Income (Loss) [Line Items]
Net income (loss)	41.7	20.9
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments, net	0.0	0.0
Unrealized losses on derivative contracts, net	(3.3)	(0.1)
Amortization of prior service costs and actuarial losses, net	5.1	5.4
Total other comprehensive (loss) income, net of tax	1.8	5.3
Comprehensive income	43.5	26.2
Issuer
Supplemental Guarantor Financial Information Statements Of Comprehensive Income (Loss) [Line Items]
Net income (loss)	25.2	(9.2)
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments, net	0.0	0.0
Unrealized losses on derivative contracts, net	0.0	0.0
Amortization of prior service costs and actuarial losses, net	0.0	0.0
Total other comprehensive (loss) income, net of tax	0.0	0.0
Comprehensive income	25.2	(9.2)
Subsidiary Non-Guarantor
Supplemental Guarantor Financial Information Statements Of Comprehensive Income (Loss) [Line Items]
Net income (loss)	90.0	59.8
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments, net	(8.3)	12.4
Unrealized losses on derivative contracts, net	0.0	0.0
Amortization of prior service costs and actuarial losses, net	0.6	0.0
Total other comprehensive (loss) income, net of tax	(7.7)	12.4
Comprehensive income	82.3	72.2
Eliminations
Supplemental Guarantor Financial Information Statements Of Comprehensive Income (Loss) [Line Items]
Net income (loss)	(115.2)	(50.6)
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments, net	0.0	0.0
Unrealized losses on derivative contracts, net	0.0	0.0
Amortization of prior service costs and actuarial losses, net	0.0	0.0
Total other comprehensive (loss) income, net of tax	0.0	0.0
Comprehensive income	$ (115.2)	$ (50.6)