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Contingencies And Commitments (European Commission Matters) (Narrative) (Details) In Millions, unless otherwise specified | 1 Months Ended | 3 Months Ended | 1 Months Ended |  |  | 1 Months Ended |
--- | --- | --- | --- | --- | --- | --- | ---
Jan. 31, 2007 D | Mar. 31, 2012 | Jul. 31, 2006 Italian Government [Member] Y | Nov. 19, 2009 Italian Government [Member] USD ($) | Jan. 31, 2007 Tariffs Granted By Spain [Member] USD ($) | Jan. 31, 2007 Tariffs Granted By Spain [Member] EUR (€) | Jan. 31, 2007 Spanish Government [Member] | Nov. 19, 2009 Maximum [Member] Italian Government [Member] USD ($) | Nov. 19, 2009 Minimum [Member] Italian Government [Member] USD ($)
Loss Contingencies [Line Items] |  |  |  |  |  |  |  |  |
Number of years operating under a power supply structure |  |  | 10 |  |  |  | 9 |  |
Italian Government extended tariff charge |  |  |  |  |  |  |  | $ 500 | $ 300
Charge related to European commission announcement |  |  |  | 250 |  |  |  |  |
Write-off of receivable |  |  |  | 20 |  |  |  |  |
Days provided to submit observations and comments to the EC | 30 |  |  |  |  |  |  |  |
Amount of curtailment, in kmt-per year |  | 44,000 |  |  |  |  |  |  |
Current agreement expiration date |  | 2012 |  |  |  |  |  |  |
Loss contingency, range of possible loss, maximum |  |  |  |  | $ 90 | € 70 |  |  |

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