Business Segments (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012
Segment Reporting Information [Line Items]
Total sales	$ 1,214.7	$ 1,394.7
Intersegment sales	35.3	42.2
Sales to external customers	1,179.4	1,352.5
Segment Operating Profit (Loss)	78.3	163.2
Corporate Expenses	(12.4)	(21.7)
Interest expense, net	14.4	19.9
Other Expense	(3.7)	(6.9)
Retirement Benefit Expense	(32.5)	(30.6)
Income Before Income Taxes	15.3	84.1
[HighPerformanceMetalsMember]
Segment Reporting Information [Line Items]
Total sales	538.3	607.7
Intersegment sales	19.9	26.4
Sales to external customers	518.4	581.3
Segment Operating Profit (Loss)	75.3	104.1
[FlatRolledProductsMember]
Segment Reporting Information [Line Items]
Total sales	562.6	643.2
Intersegment sales	4.5	7.2
Sales to external customers	558.1	636.0
Segment Operating Profit (Loss)	2.4	46.8
[EngineeredProductsMember]
Segment Reporting Information [Line Items]
Total sales	113.8	143.8
Intersegment sales	10.9	8.6
Sales to external customers	102.9	135.2
Segment Operating Profit (Loss)	$ 0.6	$ 12.3

corporate office expenses not allocable to business segments

No definition available.

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- Definition

Sum of segment operating profit, corporate expenses, net interest income or expense, retirement benefit income or expenses, and other expenses including closed company operations, nonoperating income (expense) before income (loss) from equity method investments, income taxes, extraordinary items, cumulative effects of changes in accounting principles, and noncontrolling interest.

+ References

No definition available.

+ Details

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- Definition

Net interest expense - the cost of borrowed funds as interest charged against earnings during the period net of interest income derived from investments in debt securities and on cash and cash equivalents.

+ References

No definition available.

+ Details

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- Definition

Other expense, net of gains on asset sales primarily includes charges incurred in connection with closed operations and other non-operating income or expense

+ References

No definition available.

+ Details

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- Definition

Represents defined benefit plan pension expense, and other postretirement benefit expense for both defined benefit and defined contribution plans

+ References

No definition available.

+ Details

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- Definition

Business segment operating profit, which excludes costs for restructuring charges, retirement benefit income or expense, corproate expenses, interest expense, debt extinguishment costs and costs associated with closed operations. These costs are excluded for segment reporting to provide a profit measure based on what management considers to be controllable costs at the business segment level

+ References

No definition available.

+ Details

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- Definition

Aggregate revenue recognized during the period (derived from goods sold, services rendered, insurance premiums, or other activities that constitute an entity's earning process). For financial services companies, also includes investment and interest income, and sales and trading gains.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1)

-URI http://asc.fasb.org/extlink&oid=6880815&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Article 5

+ Details

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- Definition

Amount of revenue from transactions with other operating segments of the same entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 131

-Paragraph 27

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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- Details

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- Definition

Amount of total revenue for the reportable segments, including revenue from external customers, transactions with other operating segments of the same entity, and (gross) interest revenue. All considered to be "operating revenue" for purposes of the taxonomy.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 280

-SubTopic 10

-Section 50

-Paragraph 22

-Subparagraph (a),(b),(c)

-URI http://asc.fasb.org/extlink&oid=6534315&loc=d3e8736-108599

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 131

-Paragraph 27

-Subparagraph a, b, c

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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