Long-Term Debt (Schedule of Debt) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Debt Instrument [Line Items]
Long-term debt	$ 670.5	$ 602.0
Less: Current portion of long-term debt	10.2	6.9
Total long-term debt	660.3	595.1
Senior Notes Due 2018
Debt Instrument [Line Items]
Debt discount	8.0	8.8
Exchangeable Notes
Debt Instrument [Line Items]
Debt discount	0.8	0.9
China Loan Facility
Debt Instrument [Line Items]
Debt discount	1.1	1.0
Line of Credit \| ABL Facility
Debt Instrument [Line Items]
Long-term debt	0	0
Senior Notes \| Senior Notes Due 2018
Debt Instrument [Line Items]
Long-term debt	492.0	491.2
Senior Subordinated Notes \| Exchangeable Notes
Debt Instrument [Line Items]
Long-term debt	44.2	44.1
Notes Payable to Banks \| China Loan Facility
Debt Instrument [Line Items]
Long-term debt	120.4	55.9
Other
Debt Instrument [Line Items]
Long-term debt	$ 13.9	$ 10.8

The amount of debt discount (net of debt premium) that was originally recognized at the issuance of the instrument that has yet to be amortized.

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

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

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-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28555-108399

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28567-108399

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

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Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 1A

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28541-108399

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 21

-Paragraph 20

-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.

+ Details

- Definition

Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References+ Details

Aleris International, Inc. 10-Q