Condensed Consolidating Financial Statements (Balance Sheets) (Details) - USD ($) $ in Millions	Jun. 30, 2018	Jan. 01, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
Current Assets:
Cash and cash equivalents	$ 39.4		$ 68.2	$ 61.3	$ 50.2
Accounts and notes receivable, net	741.3	$ 514.8	506.5
Inventories, net	540.2		484.2
Assets held for sale	11.6		0.0
Other assets	53.3		78.4
Total current assets	1,385.8		1,137.3
Property, plant and equipment, net	371.0		397.8
Goodwill	186.8		200.5
Investment in subsidiaries	0.0		0.0
Deferred income taxes	89.2		94.4
Other assets, net	66.6		61.5
Intercompany receivables (payables), net	0.0		0.0
Total assets	2,099.4		1,891.5
Current Liabilities:
Short-term debt	3.8		0.9
Current maturities of long-term debt	29.8		32.6
Accounts payable	437.5	$ 357.9	348.6
Accrued expenses	253.6		270.3
Liabilities held for sale	7.4		0.0
Income taxes (receivable) payable	12.0		2.1
Total current liabilities	744.1		654.5
Long-term debt	1,319.0		970.5
Post-retirement benefits, other than pensions	2.5		2.6
Pensions	86.5		84.5
Other liabilities	127.5		129.3
Total liabilities	2,279.6		1,841.4
Commitments and contingencies
Total stockholders' equity	(180.2)		50.1
Total liabilities and stockholders' equity	2,099.4		1,891.5
Eliminations [Member]
Current Assets:
Cash and cash equivalents	0.0		0.0	0.0	0.0
Accounts and notes receivable, net	0.0		0.0
Inventories, net	(5.2)		(3.4)
Assets held for sale	0.0
Other assets	(33.7)		(28.4)
Total current assets	(38.9)		(31.8)
Property, plant and equipment, net	(3.9)		(4.2)
Goodwill	0.0		0.0
Investment in subsidiaries	(2,266.2)		(1,622.9)
Deferred income taxes	(12.2)		(12.2)
Other assets, net	(1.5)		(1.5)
Intercompany receivables (payables), net	(73.7)		(102.8)
Total assets	(2,396.4)		(1,775.4)
Current Liabilities:
Short-term debt	0.0		0.0
Current maturities of long-term debt	0.0		0.0
Accounts payable	0.0		0.0
Accrued expenses	0.0		0.0
Liabilities held for sale	0.0
Income taxes (receivable) payable	(50.9)		(50.8)
Total current liabilities	(50.9)		(50.8)
Long-term debt	0.0		0.0
Post-retirement benefits, other than pensions	0.0		0.0
Pensions	0.0		0.0
Other liabilities	0.0		0.0
Total liabilities	(50.9)		(50.8)
Commitments and contingencies
Total stockholders' equity	(2,345.5)		(1,724.6)
Total liabilities and stockholders' equity	(2,396.4)		(1,775.4)
Parent [Member]
Current Assets:
Cash and cash equivalents	1.6		1.6	3.4	1.2
Accounts and notes receivable, net	0.0		0.0
Inventories, net	0.0		0.0
Assets held for sale	0.0
Other assets	4.0		16.2
Total current assets	5.6		17.8
Property, plant and equipment, net	0.0		0.0
Goodwill	0.0		0.0
Investment in subsidiaries	1,668.2		1,257.7
Deferred income taxes	7.4		3.9
Other assets, net	1.5		2.1
Intercompany receivables (payables), net	(771.2)		(559.3)
Total assets	911.5		722.2
Current Liabilities:
Short-term debt	0.0		0.0
Current maturities of long-term debt	29.4		29.4
Accounts payable	25.8		21.3
Accrued expenses	4.3		3.1
Liabilities held for sale	0.0
Income taxes (receivable) payable	14.8		(64.5)
Total current liabilities	74.3		(10.7)
Long-term debt	1,017.4		682.8
Post-retirement benefits, other than pensions	0.0		0.0
Pensions	0.0		0.0
Other liabilities	0.0		0.0
Total liabilities	1,091.7		672.1
Commitments and contingencies
Total stockholders' equity	(180.2)		50.1
Total liabilities and stockholders' equity	911.5		722.2
Guarantor Subsidiaries [Member]
Current Assets:
Cash and cash equivalents	22.6		28.0	24.9	17.1
Accounts and notes receivable, net	67.5		35.3
Inventories, net	442.9		355.7
Assets held for sale	0.0
Other assets	27.5		23.1
Total current assets	560.5		442.1
Property, plant and equipment, net	260.7		257.6
Goodwill	166.2		134.9
Investment in subsidiaries	598.5		365.8
Deferred income taxes	69.0		69.1
Other assets, net	46.9		41.3
Intercompany receivables (payables), net	718.9		554.7
Total assets	2,420.7		1,865.5
Current Liabilities:
Short-term debt	0.0		0.0
Current maturities of long-term debt	0.1		2.9
Accounts payable	301.1		228.0
Accrued expenses	208.5		209.4
Liabilities held for sale	0.0
Income taxes (receivable) payable	11.4		56.5
Total current liabilities	521.1		496.8
Long-term debt	11.6		11.7
Post-retirement benefits, other than pensions	2.5		2.6
Pensions	77.8		74.7
Other liabilities	119.7		120.6
Total liabilities	732.7		706.4
Commitments and contingencies
Total stockholders' equity	1,688.0		1,159.1
Total liabilities and stockholders' equity	2,420.7		1,865.5
Non-Guarantor Subsidiaries [Member]
Current Assets:
Cash and cash equivalents	15.2		38.6	$ 33.0	$ 31.9
Accounts and notes receivable, net	673.8		471.2
Inventories, net	102.5		131.9
Assets held for sale	11.6
Other assets	55.5		67.5
Total current assets	858.6		709.2
Property, plant and equipment, net	114.2		144.4
Goodwill	20.6		65.6
Investment in subsidiaries	(0.5)		(0.6)
Deferred income taxes	25.0		33.6
Other assets, net	19.7		19.6
Intercompany receivables (payables), net	126.0		107.4
Total assets	1,163.6		1,079.2
Current Liabilities:
Short-term debt	3.8		0.9
Current maturities of long-term debt	0.3		0.3
Accounts payable	110.6		99.3
Accrued expenses	40.8		57.8
Liabilities held for sale	7.4
Income taxes (receivable) payable	36.7		60.9
Total current liabilities	199.6		219.2
Long-term debt	290.0		276.0
Post-retirement benefits, other than pensions	0.0		0.0
Pensions	8.7		9.8
Other liabilities	7.8		8.7
Total liabilities	506.1		513.7
Commitments and contingencies
Total stockholders' equity	657.5		565.5
Total liabilities and stockholders' equity	$ 1,163.6		$ 1,079.2