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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
-Subparagraph (SX 210.4-08.(h)(1)(i))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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Amount of restructuring charges, remediation cost, and asset impairment loss.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.3)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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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
-SubTopic 10
-Section S99
-Paragraph 2
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Business Segments (Details) $ in Millions	3 Months Ended			6 Months Ended
Business Segments (Details) $ in Millions	Jun. 30, 2017 USD ($) segment	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)
Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Abstract]
Number of business segments \| segment	2
Segment Reporting Information [Line Items]
Sales	$ 880.2	$ 810.5		$ 1,746.1	$ 1,568.0
Operating profit (loss):	70.9	7.0		140.8	(73.5)
LIFO and net realizable value reserves	(0.1)	0.4		(0.1)	0.4
Corporate expenses	(11.8)	(11.8)		(22.1)	(22.8)
Closed operations and other expenses	(13.2)	(5.7)		(16.2)	(9.2)
Restructuring charges	0.0	1.0	$ 9.0	0.0	10.0
Interest expense, net	(34.5)	(30.3)		(68.0)	(58.6)
Income (loss) before income tax provision (benefit)	11.3	(41.4)		34.4	(173.7)
High Performance Materials & Components
Segment Reporting Information [Line Items]
Operating profit (loss):	68.0	38.8		118.9	67.9
Flat Rolled Products
Segment Reporting Information [Line Items]
Operating profit (loss):	2.9	(31.8)		21.9	(141.4)
Operating Segments
Segment Reporting Information [Line Items]
Sales	916.5	835.4		1,813.2	1,624.5
Operating Segments \| High Performance Materials & Components
Segment Reporting Information [Line Items]
Sales	543.3	511.1		1,067.0	1,019.0
Operating Segments \| Flat Rolled Products
Segment Reporting Information [Line Items]
Sales	373.2	324.3		746.2	605.5
Internal Customers \| Operating Segments
Segment Reporting Information [Line Items]
Sales	36.3	24.9		67.1	56.5
Internal Customers \| Operating Segments \| High Performance Materials & Components
Segment Reporting Information [Line Items]
Sales	16.9	12.7		30.2	27.6
Internal Customers \| Operating Segments \| Flat Rolled Products
Segment Reporting Information [Line Items]
Sales	19.4	12.2		36.9	28.9
External Customers \| Operating Segments
Segment Reporting Information [Line Items]
Sales	880.2	810.5		1,746.1	1,568.0
External Customers \| Operating Segments \| High Performance Materials & Components
Segment Reporting Information [Line Items]
Sales	526.4	498.4		1,036.8	991.4
External Customers \| Operating Segments \| Flat Rolled Products
Segment Reporting Information [Line Items]
Sales	$ 353.8	$ 312.1		$ 709.3	$ 576.6