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Commitments, Contingencies and Legal Proceedings - Additional Information (Detail) (USD $) | 9 Months Ended
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Sep. 30, 2013 Operable_Unit
Commitments And Contingencies Disclosure [Abstract] |
Aggregate of response actions response costs and NRDs | $ 1,000,000,000
Number of operable units | 5
Cost of response incurred by government | 4,280,000
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
Annual estimated cost rate seeks by government | 70,000,000
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 environmental liability, current portion | 100,000
Reserve for claiming liability | 16,300,000
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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