Environmental Compliance (Narrative) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Environmental Compliance
Depleted uranium disposition	$ 0.2	$ 145.2
Accrued liabilities for stored wastes	2.1
Accrued liabilities for lease turnover costs, total	42.5
Accrued liabilities for lease turnover costs, current	32.2
Accrued liabilities for lease turnover costs, noncurrent	$ 10.3	$ 42.6

Sum of the carrying values as of the balance sheet date of obligations incurred through that date and due after one year (or beyond the operating cycle if longer), including liabilities for compensation costs, fringe benefits other than pension and postretirement obligations, rent, contractual rights and obligations, and statutory obligations.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.24)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 24

-Article 5

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