Financial Information for Subsidiary and Guarantor Parent (Cash Flows) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Financial Statements, Captions [Line Items]
Cash flows provided by (used in) operating activities	$ 22.4	$ (43.7)	$ 131.4
Purchases of property, plant and equipment	(122.7)	(202.2)	(144.5)
Net receipts (payments) on intercompany activity	0.0	0.0	0.0
Purchases of businesses, net of cash acquired	0.0	0.0	(0.5)
Asset disposals and other	3.1	2.2	(0.1)
Cash flows provided by (used in) investing activities	(119.6)	(200.0)	(145.1)
Borrowings on long-term debt	8.5	387.5	0.0
Payments on long-term debt and capital leases	(353.0)	(2.7)	(23.6)
Net borrowings under credit facilities	1.6	3.1	1.5
Debt issuance costs	(0.8)	(10.4)	0.0
Debt extinguishment charge	(35.8)	0.0	0.0
Net receipts (payments) on intercompany activity	0.0	0.0	0.0
Issuance of common stock	397.8	0.0	0.0
Dividends paid to stockholders	0.0	(25.8)	(66.5)
Dividends paid to noncontrolling interests	(8.0)	(16.0)	(16.0)
Sale to noncontrolling interest	3.7	0.0	0.0
Acquisition of noncontrolling interests	0.0	(12.2)	0.0
Shares repurchased for income tax withholding on share-based compensation	(4.8)	0.0	(1.4)
Other			0.1
Cash provided by (used in) financing activities	9.2	323.5	(106.0)
Increase (decrease) in cash and cash equivalents	(88.0)	79.8	(119.7)
Legal Entities [Member] \| Guarantor Parent [Member]
Condensed Financial Statements, Captions [Line Items]
Cash flows provided by (used in) operating activities	(78.8)	(78.5)	(70.0)
Purchases of property, plant and equipment	(0.9)	(0.5)	(0.6)
Net receipts (payments) on intercompany activity	0.0	0.0	0.0
Purchases of businesses, net of cash acquired			0.0
Asset disposals and other	0.0	0.0	0.0
Cash flows provided by (used in) investing activities	(0.9)	(0.5)	(0.6)
Borrowings on long-term debt	0.0	287.5
Payments on long-term debt and capital leases	(350.4)	(0.7)	(0.6)
Net borrowings under credit facilities	0.0	0.0
Debt issuance costs	0.0	(9.4)
Debt extinguishment charge	(35.8)
Net receipts (payments) on intercompany activity	72.7	(170.7)	137.3
Issuance of common stock	397.8
Dividends paid to stockholders	0.0	(25.8)	(66.5)
Dividends paid to noncontrolling interests	0.0	0.0	0.0
Sale to noncontrolling interest	0.0
Acquisition of noncontrolling interests		0.0
Shares repurchased for income tax withholding on share-based compensation	(4.8)
Other			(1.4)
Cash provided by (used in) financing activities	79.5	80.9	68.8
Increase (decrease) in cash and cash equivalents	(0.2)	1.9	(1.8)
Legal Entities [Member] \| Subsidiary [Member]
Condensed Financial Statements, Captions [Line Items]
Cash flows provided by (used in) operating activities	(101.5)	(232.3)	(134.8)
Purchases of property, plant and equipment	(38.5)	(98.7)	(66.9)
Net receipts (payments) on intercompany activity	0.0	0.0	0.0
Purchases of businesses, net of cash acquired			0.0
Asset disposals and other	0.1	0.2	0.2
Cash flows provided by (used in) investing activities	(38.4)	(98.5)	(66.7)
Borrowings on long-term debt	0.0	0.0
Payments on long-term debt and capital leases	(0.3)	(0.2)	(0.1)
Net borrowings under credit facilities	0.0	0.0
Debt issuance costs	0.0	0.0
Debt extinguishment charge	0.0
Net receipts (payments) on intercompany activity	151.2	330.7	190.6
Issuance of common stock	0.0
Dividends paid to stockholders	0.0	0.0	0.0
Dividends paid to noncontrolling interests	0.0	0.0	0.0
Sale to noncontrolling interest	0.0
Acquisition of noncontrolling interests		0.0
Shares repurchased for income tax withholding on share-based compensation	0.0
Other			0.0
Cash provided by (used in) financing activities	150.9	330.5	190.5
Increase (decrease) in cash and cash equivalents	11.0	(0.3)	(11.0)
Legal Entities [Member] \| Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Cash flows provided by (used in) operating activities	214.7	291.1	360.2
Purchases of property, plant and equipment	(83.3)	(103.0)	(77.0)
Net receipts (payments) on intercompany activity	(223.9)	(160.0)	(327.9)
Purchases of businesses, net of cash acquired			(0.5)
Asset disposals and other	3.0	2.0	(0.3)
Cash flows provided by (used in) investing activities	(304.2)	(261.0)	(405.7)
Borrowings on long-term debt	8.5	100.0
Payments on long-term debt and capital leases	(2.3)	(1.8)	(22.9)
Net borrowings under credit facilities	1.6	3.1
Debt issuance costs	(0.8)	(1.0)
Debt extinguishment charge	0.0
Net receipts (payments) on intercompany activity	0.0	0.0	0.0
Issuance of common stock	0.0
Dividends paid to stockholders	(12.0)	(24.0)	(24.0)
Dividends paid to noncontrolling interests	(8.0)	(16.0)	(16.0)
Sale to noncontrolling interest	3.7
Acquisition of noncontrolling interests		(12.2)
Shares repurchased for income tax withholding on share-based compensation	0.0
Other			1.5
Cash provided by (used in) financing activities	(9.3)	48.1	(61.4)
Increase (decrease) in cash and cash equivalents	(98.8)	78.2	(106.9)
Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Cash flows provided by (used in) operating activities	(12.0)	(24.0)	(24.0)
Purchases of property, plant and equipment	0.0	0.0	0.0
Net receipts (payments) on intercompany activity	223.9	160.0	327.9
Purchases of businesses, net of cash acquired			0.0
Asset disposals and other	0.0	0.0	0.0
Cash flows provided by (used in) investing activities	223.9	160.0	327.9
Borrowings on long-term debt	0.0	0.0
Payments on long-term debt and capital leases	0.0	0.0	0.0
Net borrowings under credit facilities	0.0	0.0
Debt issuance costs	0.0	0.0
Debt extinguishment charge	0.0
Net receipts (payments) on intercompany activity	(223.9)	(160.0)	(327.9)
Issuance of common stock	0.0
Dividends paid to stockholders	12.0	24.0	24.0
Dividends paid to noncontrolling interests	0.0	0.0	0.0
Sale to noncontrolling interest	0.0
Acquisition of noncontrolling interests		0.0
Shares repurchased for income tax withholding on share-based compensation	0.0
Other			0.0
Cash provided by (used in) financing activities	(211.9)	(136.0)	(303.9)
Increase (decrease) in cash and cash equivalents	$ 0.0	$ 0.0	$ 0.0

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