Supplemental Financial Information (Accounts Receivable, Net) (Details) (USD $) In Millions | Sep. 30, 2011 | Dec. 31, 2010 |
|---|---|---|
| Supplemental Information For Property, Casualty Insurance Underwriters [Line Items] | ||
| Accounts receivable | $ 666.9 | $ 217.7 |
| Allowance for doubtful accounts | (12.0) | (3.1) |
| Accounts receivable, net | 654.9 | 214.6 |
Trade [Member] | ||
| Supplemental Information For Property, Casualty Insurance Underwriters [Line Items] | ||
| Accounts receivable | 624.2 | 209.9 |
Other [Member] | ||
| Supplemental Information For Property, Casualty Insurance Underwriters [Line Items] | ||
| Accounts receivable | $ 42.7 | $ 7.8 |