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Contingencies and Commitments - Additional Information - 1 (Detail) In Millions, unless otherwise specified | 1 Months Ended | 12 Months Ended |  | 12 Months Ended | 1 Months Ended |  | 12 Months Ended |  | 12 Months Ended |  | 12 Months Ended | 3 Months Ended | 12 Months Ended
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Jan. 31, 2007 | Dec. 31, 2013 USD ($) | Dec. 31, 2012 USD ($) | Jun. 12, 2012 USD ($) | Jun. 12, 2012 EUR (€) | Dec. 31, 2013 Minimum [Member] | Dec. 31, 2013 Maximum [Member] | Dec. 31, 2013 Recurring Costs of Managing Hazardous Substances and Environmental Programs [Member] | Jan. 31, 2007 Spanish Government [Member] | Jan. 31, 2007 Tariffs Granted by Spain [Member] USD ($) | Jan. 31, 2007 Tariffs Granted by Spain [Member] EUR (€) | Dec. 31, 2013 Massena West, NY [Member] USD ($) | Dec. 31, 2012 Massena West, NY [Member] USD ($) | Dec. 31, 2012 Smelter Sites [Member] USD ($) | Dec. 31, 2012 Smelter Sites [Member] Canada and Norway [Member] USD ($) | Dec. 31, 2012 East St. Louis, IL Site [Member] USD ($) | Dec. 31, 2005 East St. Louis, IL Site [Member] USD ($) | Dec. 31, 2013 East St. Louis, IL Site [Member] USD ($) | Dec. 31, 2012 Sherwin, TX site [Member] USD ($) | Dec. 31, 2013 Sherwin, TX site [Member] USD ($) | Dec. 31, 2013 Other Sites [Member] USD ($) | Dec. 31, 2012 Other Sites [Member] USD ($) | Dec. 31, 2013 U.S. Smelters [Member] USD ($) | Jun. 30, 2012 Grasse River [Member] USD ($) | Dec. 31, 2013 Grasse River [Member] USD ($) | Dec. 31, 2012 Grasse River [Member] USD ($) | Dec. 31, 2013 Massena West, NY and Baie Comeau, Quebec, Canada [Member] USD ($)
Loss Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of years operating under a power supply structure |  |  |  |  |  |  |  |  | 9 years |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Days provided to submit observations and comments to the EC | 30 days |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loss contingency, range of possible loss, maximum |  |  |  | $ 418 | € 303 |  |  |  |  | $ 95 | € 70 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of cleanup locations |  | More than 100 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Remediation reserve balance |  | 509 | 532 |  |  |  |  |  |  |  |  | 241 | 243 |  |  | 26 |  | 24 | 36 | 35 |  |  |  |  |  |  |
Remediation reserve balance, classified as a current liability |  | 48 | 74 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Remediation reserve increase |  |  |  |  |  |  |  |  |  |  |  |  | 206 | 30 |  | 14 | 15 |  |  |  |  |  |  | 37 | 18 | 128 |
Remediation reserve adjustment |  |  |  |  |  |  |  |  |  |  |  |  | 165 |  | 45 | 14 |  |  |  |  | 6 | 12 | 12 |  |  |  | 12
Increase in remediation reserve |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 30 |  |  |  |  |  |  |  |
Payments related to remediation expenses applied against the reserve |  | 40 | 22 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Increase and decrease in reserves due to effects of foreign currency translation |  | (1) | 1 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage of cost of goods sold |  |  |  |  |  |  |  | 2.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Remediation alternative estimated cost |  | 243 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Adjustment of reserve related to grass river |  |  |  |  |  |  |  |  |  |  |  | $ 0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Planning and design phase period |  |  |  |  |  | 2 years | 3 years |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Actual remediation fieldwork period |  | 4 years |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Majority of the project funding Period |  |  |  |  |  | 2016 | 2020 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |

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