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Summary of Significant Accounting Policies and Basis of Presentation Summary of Significant Accounting Policies and Baiss of Presentation (Details) (Reclassification Errors [Member], USD $)
In Millions, unless otherwise specified |
3 Months Ended | 6 Months Ended | 12 Months Ended | ||||
|---|---|---|---|---|---|---|---|
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Mar. 31, 2012
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Jun. 30, 2011
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Mar. 31, 2011
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Jun. 30, 2011
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Dec. 31, 2011
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Dec. 31, 2010
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Dec. 31, 2009
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Reclassification Errors [Member]
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| Impairment charges and acquisitions costs reclassifications | $ 0.1 | $ 0.3 | $ 1.6 | $ 2.0 | $ 18.1 | $ 1.2 | $ 0.8 |