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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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The expected number of positions to be eliminated as a result of restructuring activities.

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Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
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-Section S99
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-Name Staff Accounting Bulletin (SAB)
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Aggregate revenue during the period from the sale of goods in the normal course of business, after deducting returns, allowances and discounts.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 225
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-Section S99
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Business Segments (Details) $ in Millions	3 Months Ended			6 Months Ended
Business Segments (Details) $ in Millions	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($) segment	Jun. 30, 2015 USD ($)
Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Abstract]
Number of business segments \| segment				2
Segment Reporting Information [Line Items]
Sales	$ 810.5		$ 1,022.5	$ 1,568.0	$ 2,148.0
Operating profit (loss):	7.0		21.2	(73.5)	87.3
LIFO and net realizable value reserves	0.4		0.2	0.4	0.2
Corporate expenses	(11.8)		(10.1)	(22.8)	(22.9)
Closed company and other expenses	(5.7)		(6.1)	(9.2)	(12.1)
Restructuring charges	(1.0)	$ (9.0)	0.0	(10.0)	0.0
Interest expense, net	(30.3)		(26.8)	(58.6)	(53.5)
Income (loss) before income tax provision (benefit)	(41.4)		(21.6)	(173.7)	(1.0)
Restructuring Reserve	$ 11.0			11.0
High Performance Materials & Components
Segment Reporting Information [Line Items]
Restructuring and Related Cost, Expected Number of Positions Eliminated	20
Operating profit (loss):	$ 38.8		44.4	67.9	117.3
Flat Rolled Products
Segment Reporting Information [Line Items]
Restructuring and Related Cost, Expected Number of Positions Eliminated		250
Operating profit (loss):	(31.8)		(23.2)	(141.4)	(30.0)
Operating Segments
Segment Reporting Information [Line Items]
Sales	835.4		1,067.0	1,624.5	2,236.6
Operating Segments \| High Performance Materials & Components
Segment Reporting Information [Line Items]
Sales	511.1		533.5	1,019.0	1,098.4
Operating Segments \| Flat Rolled Products
Segment Reporting Information [Line Items]
Sales	324.3		533.5	605.5	1,138.2
Internal Customers \| Operating Segments
Segment Reporting Information [Line Items]
Sales	24.9		44.5	56.5	88.6
Internal Customers \| Operating Segments \| High Performance Materials & Components
Segment Reporting Information [Line Items]
Sales	12.7		22.4	27.6	44.5
Internal Customers \| Operating Segments \| Flat Rolled Products
Segment Reporting Information [Line Items]
Sales	12.2		22.1	28.9	44.1
External Customers \| Operating Segments
Segment Reporting Information [Line Items]
Sales	810.5		1,022.5	1,568.0	2,148.0
External Customers \| Operating Segments \| High Performance Materials & Components
Segment Reporting Information [Line Items]
Sales	498.4		511.1	991.4	1,053.9
External Customers \| Operating Segments \| Flat Rolled Products
Segment Reporting Information [Line Items]
Sales	$ 312.1		$ 511.4	$ 576.6	$ 1,094.1