SUPPLEMENTAL CONDENSED CONSOLIDATING FINANCIAL INFORMATION - Condensed Consolidating Statement of Cash Flows (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities			$ 92.1	$ 90.2
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property, plant and equipment	$ (10.5)	$ (11.4)	(28.6)	(32.2)
Payments for acquisitions, net of cash acquired			0.0	(72.3)
Proceeds from disposals of businesses and property, plant and equipment			1.2	18.6
Purchases of environmental credits			0.0	(2.8)
Proceeds from eminent domain matter and property insurance claims			6.0	2.1
Investment in subsidiaries			0.0
Net cash used in investing activities			(21.4)	(86.6)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from revolver borrowings			273.3	338.2
Repayments of revolver borrowings			(277.2)	(310.7)
Proceeds from exercise of stock options			0.2	0.1
Payments of other long-term obligations			(33.4)	(5.6)
Payments for other financing			(24.2)	(21.5)
Treasury share purchases			(2.2)	(1.9)
Other proceeds			0.0	0.5
Intercompany funding			0.0	0.0
Net cash used in financing activities			(63.5)	(0.9)
EFFECT OF EXCHANGE RATES ON CASH AND CASH EQUIVALENTS			(0.2)	(0.1)
NET INCREASE IN CASH AND CASH EQUIVALENTS			7.0	2.6
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD			20.0	22.6
CASH AND CASH EQUIVALENTS AT END OF PERIOD	27.0	25.2	27.0	25.2
Reportable Legal Entities | Parent
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities			(24.0)	(20.8)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property, plant and equipment			0.0	0.0
Payments for acquisitions, net of cash acquired				0.0
Proceeds from disposals of businesses and property, plant and equipment			0.0	0.0
Purchases of environmental credits				0.0
Proceeds from eminent domain matter and property insurance claims			0.0	0.0
Investment in subsidiaries			1.0
Net cash used in investing activities			1.0	0.0
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from revolver borrowings			273.3	338.2
Repayments of revolver borrowings			(277.2)	(310.7)
Proceeds from exercise of stock options			0.2	0.1
Payments of other long-term obligations			(0.8)	(2.2)
Payments for other financing			(0.2)	0.0
Treasury share purchases			(2.2)	(1.9)
Other proceeds				0.0
Intercompany funding			29.9	(2.7)
Net cash used in financing activities			23.0	20.8
EFFECT OF EXCHANGE RATES ON CASH AND CASH EQUIVALENTS			0.0	0.0
NET INCREASE IN CASH AND CASH EQUIVALENTS			0.0	0.0
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD			0.0	0.0
CASH AND CASH EQUIVALENTS AT END OF PERIOD	0.0	0.0	0.0	0.0
Reportable Legal Entities | Guarantor Subsidiaries
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities			103.6	108.5
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property, plant and equipment			(25.4)	(29.3)
Payments for acquisitions, net of cash acquired				(72.3)
Proceeds from disposals of businesses and property, plant and equipment			1.2	18.6
Purchases of environmental credits				0.0
Proceeds from eminent domain matter and property insurance claims			5.3	1.6
Investment in subsidiaries			0.0
Net cash used in investing activities			(18.9)	(81.4)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from revolver borrowings			0.0	0.0
Repayments of revolver borrowings			0.0	0.0
Proceeds from exercise of stock options			0.0	0.0
Payments of other long-term obligations			(32.6)	(3.4)
Payments for other financing			(23.6)	(20.6)
Treasury share purchases			0.0	0.0
Other proceeds				0.5
Intercompany funding			(21.5)	4.3
Net cash used in financing activities			(77.7)	(19.2)
EFFECT OF EXCHANGE RATES ON CASH AND CASH EQUIVALENTS			0.0	0.0
NET INCREASE IN CASH AND CASH EQUIVALENTS			7.0	7.9
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD			10.8	7.0
CASH AND CASH EQUIVALENTS AT END OF PERIOD	17.8	14.9	17.8	14.9
Reportable Legal Entities | Non-Guarantor Subsidiaries
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities			7.3	2.8
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property, plant and equipment			(3.2)	(2.9)
Payments for acquisitions, net of cash acquired				0.0
Proceeds from disposals of businesses and property, plant and equipment			0.0	0.0
Purchases of environmental credits				(2.8)
Proceeds from eminent domain matter and property insurance claims			0.7	0.5
Investment in subsidiaries			0.0
Net cash used in investing activities			(2.5)	(5.2)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from revolver borrowings			0.0	0.0
Repayments of revolver borrowings			0.0	0.0
Proceeds from exercise of stock options			0.0	0.0
Payments of other long-term obligations			0.0	0.0
Payments for other financing			(0.4)	(0.9)
Treasury share purchases			0.0	0.0
Other proceeds				0.0
Intercompany funding			(4.2)	(1.9)
Net cash used in financing activities			(4.6)	(2.8)
EFFECT OF EXCHANGE RATES ON CASH AND CASH EQUIVALENTS			(0.2)	(0.1)
NET INCREASE IN CASH AND CASH EQUIVALENTS			0.0	(5.3)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD			9.2	15.6
CASH AND CASH EQUIVALENTS AT END OF PERIOD	9.2	10.3	9.2	10.3
Eliminations
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities			5.2	(0.3)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property, plant and equipment			0.0	0.0
Payments for acquisitions, net of cash acquired				0.0
Proceeds from disposals of businesses and property, plant and equipment			0.0	0.0
Purchases of environmental credits				0.0
Proceeds from eminent domain matter and property insurance claims			0.0	0.0
Investment in subsidiaries			(1.0)
Net cash used in investing activities			(1.0)	0.0
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from revolver borrowings			0.0	0.0
Repayments of revolver borrowings			0.0	0.0
Proceeds from exercise of stock options			0.0	0.0
Payments of other long-term obligations			0.0	0.0
Payments for other financing			0.0	0.0
Treasury share purchases			0.0	0.0
Other proceeds				0.0
Intercompany funding			(4.2)	0.3
Net cash used in financing activities			(4.2)	0.3
EFFECT OF EXCHANGE RATES ON CASH AND CASH EQUIVALENTS			0.0	0.0
NET INCREASE IN CASH AND CASH EQUIVALENTS			0.0	0.0
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD			0.0	0.0
CASH AND CASH EQUIVALENTS AT END OF PERIOD	$ 0.0	$ 0.0	$ 0.0	$ 0.0