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Commitments, Contingencies and Legal Proceedings (Details Textual) (USD $) | 12 Months Ended |
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Dec. 31, 2012 EnforcementAction OperableUnit | Jan. 31, 2008 Respondents
Commitments Contingencies and Legal Proceedings (Textual) [Abstract] |  |
Annual payments due under operating leases | $ 21,100,000 |
Aggregated contractual obligation | 203,700,000 |
Aggregate of response actions response costs and NRDs | 1,000,000,000 |
Number of operable units | 5 |
Number of principal enforcement actions | 2 |
Number of Respondents |  | 2
Cost of response incurred by government | 4,280,000 |
Estimated cost of remediation made by government to all parties | 1,000,000,000 |
Reasonable outside estimate for cost of remediation made by government to all parties | 1,500,000,000 |
Estimated future cost of work yet to be done | 360,000,000 |
Initial minimum amount of NRD assessment | 176,000,000 |
Initial maximum amount of NRD assessment | 333,000,000 |
Revised minimum amount of NRD assessment | 287,000,000 |
Revised maximum amount of NRD assessment | 423,000,000 |
The limitation period for the NRD's claims | 3 years |
Reserve for claiming liability | 16,400,000 |
Reserve for environmental liability, current portion | 100,000 |
Maximum estimated percentage of discharge | 27.00% |
Maximum estimated cost related to Fox River Matter | $ 275,000,000 |
Period over which estimated cost accrued | 10 years |

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