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Significant Accounting Policies Trade Receivables and Allowance for Doubtful Accounts (Details) (USD $) In Millions, unless otherwise specified | Dec. 31, 2012 D | Dec. 31, 2011
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Valuation and Qualifying Accounts Disclosure |  |
Customer credit terms (in days) | 30 |
Allowance for Doubtful Accounts Receivable, Current | $ 0.8 | $ 0.8

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