Acquisition (Details) (Big Quill Resources, Inc. [Member], USD $) In Millions, unless otherwise specified | 9 Months Ended | |
|---|---|---|
Sep. 30, 2011 | Jan. 07, 2011 | |
Big Quill Resources, Inc. [Member] | ||
| Business Acquisition [Line Items] | ||
| Cash purchase price | $ 58.1 | |
| Increase in SOP production capacity due to acquisition (in tons) | 40,000 | |
| Purchase price allocation [Abstract] | ||
| Cash | 2.4 | |
| Receivables | 2.7 | |
| Inventories | 1.4 | |
| Other current assets | 1.1 | |
| Property, plant and equipment | 14.0 | |
| Intangible assets | 37.3 | |
| Goodwill | 14.6 | |
| Liabilities assumed | (1.9) | |
| Deferred income taxes | (11.1) | |
| Total preliminary purchase price | $ 60.5 | |
| Amortization period for acquired intangible asset (in years) | 50 |