SUPPLEMENTAL GUARANTOR FINANCIAL INFORMATION (Cash Flows)(Details) - USD ($) $ in Millions	6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Supplemental Guarantor Financial Information Statements Of Cash Flows [Line Items]
Net Cash Provided by (Used in) Operating Activities	$ 227.4	$ 186.2
Payments to Acquire Property, Plant, and Equipment	(150.9)	(137.4)
Payments to Acquire Businesses, Net of Cash Acquired	0.0	(69.5)
Payments under long-term supply contract	0.0	(85.0)	$ (175.7)
Proceeds from disposition of property, plant and equipment	0.1	0.4
Proceeds from Contributions from Affiliates		4.4
Net investing activities	(150.8)	(287.1)
Proceeds from Issuance of Long-term Debt	1,875.0	0.0
Long-term debt repayments	(1,890.1)	(159.0)
Stock options exercised	15.8	0.2
Payments of Dividends	(66.3)	(66.1)
Debt issuance costs	(11.2)	0.0
Intercompany Financing Activities	0.0
Net financing activities	(76.8)	(224.9)
Effect of exchange rate changes on cash and cash equivalents	0.2	0.4
Net decrease in cash and cash equivalents	0.0	(325.4)
Cash and cash equivalents, end of period	184.5	66.6	184.5
Parent Guarantor
Supplemental Guarantor Financial Information Statements Of Cash Flows [Line Items]
Net Cash Provided by (Used in) Operating Activities	124.4	305.4
Payments to Acquire Property, Plant, and Equipment	(43.9)	(26.8)
Payments to Acquire Businesses, Net of Cash Acquired		(69.5)
Payments under long-term supply contract		0.0
Proceeds from disposition of property, plant and equipment	0.0	0.2
Proceeds from Contributions from Affiliates		4.4
Net investing activities	(43.9)	(91.7)
Proceeds from Issuance of Long-term Debt	500.0
Long-term debt repayments	(590.4)	(125.2)
Stock options exercised	15.8	0.2
Payments of Dividends	(66.3)	(66.1)
Debt issuance costs	(8.3)	(118.8)
Intercompany Financing Activities	72.4
Net financing activities	(76.8)	(309.9)
Effect of exchange rate changes on cash and cash equivalents	0.0	0.0
Net decrease in cash and cash equivalents	3.7	(96.2)
Cash and cash equivalents, end of period	28.9	23.2	25.2
Issuer
Supplemental Guarantor Financial Information Statements Of Cash Flows [Line Items]
Net Cash Provided by (Used in) Operating Activities	0.0	0.0
Payments to Acquire Property, Plant, and Equipment	0.0	0.0
Payments to Acquire Businesses, Net of Cash Acquired		0.0
Payments under long-term supply contract		0.0
Proceeds from disposition of property, plant and equipment	0.0	0.0
Proceeds from Contributions from Affiliates		0.0
Net investing activities	0.0	0.0
Proceeds from Issuance of Long-term Debt	1,375.0
Long-term debt repayments	(1,299.7)	(33.8)
Stock options exercised	0.0	0.0
Payments of Dividends	0.0	0.0
Debt issuance costs	(2.9)	33.8
Intercompany Financing Activities	(72.4)
Net financing activities	0.0	0.0
Effect of exchange rate changes on cash and cash equivalents	0.0	0.0
Net decrease in cash and cash equivalents	0.0	0.0
Cash and cash equivalents, end of period	0.0	0.0	0.0
Subsidiary Non-Guarantor
Supplemental Guarantor Financial Information Statements Of Cash Flows [Line Items]
Net Cash Provided by (Used in) Operating Activities	103.0	(119.2)
Payments to Acquire Property, Plant, and Equipment	(107.0)	(110.6)
Payments to Acquire Businesses, Net of Cash Acquired		0.0
Payments under long-term supply contract		(85.0)
Proceeds from disposition of property, plant and equipment	0.1	0.2
Proceeds from Contributions from Affiliates		0.0
Net investing activities	(106.9)	(195.4)
Proceeds from Issuance of Long-term Debt	0.0
Long-term debt repayments	0.0	0.0
Stock options exercised	0.0	0.0
Payments of Dividends	0.0	0.0
Debt issuance costs	0.0	85.0
Intercompany Financing Activities	0.0
Net financing activities	0.0	85.0
Effect of exchange rate changes on cash and cash equivalents	0.2	0.4
Net decrease in cash and cash equivalents	(3.7)	(229.2)
Cash and cash equivalents, end of period	155.6	43.4	159.3
Eliminations
Supplemental Guarantor Financial Information Statements Of Cash Flows [Line Items]
Net Cash Provided by (Used in) Operating Activities	0.0	0.0
Payments to Acquire Property, Plant, and Equipment	0.0	0.0
Payments to Acquire Businesses, Net of Cash Acquired		0.0
Payments under long-term supply contract		0.0
Proceeds from disposition of property, plant and equipment	0.0	0.0
Proceeds from Contributions from Affiliates		0.0
Net investing activities	0.0	0.0
Proceeds from Issuance of Long-term Debt	0.0
Long-term debt repayments	0.0	0.0
Stock options exercised	0.0	0.0
Payments of Dividends	0.0	0.0
Debt issuance costs	0.0	0.0
Intercompany Financing Activities	0.0
Net financing activities	0.0	0.0
Effect of exchange rate changes on cash and cash equivalents	0.0	0.0
Net decrease in cash and cash equivalents	0.0	0.0
Cash and cash equivalents, end of period	$ 0.0	$ 0.0	$ 0.0