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Basis of Presentation (Details) (USD $) In Millions, unless otherwise specified | 3 Months Ended
--- | ---
Mar. 31, 2015 retail_customers sqmi | Mar. 31, 2014
Basis of Presentation [Abstract] |  |
Increase (Decrease) in Inventories | $ 13 us-gaap_IncreaseDecreaseInInventories | $ (2)us-gaap_IncreaseDecreaseInInventories
Service Area Sq Miles | 4,000 por_ServiceAreaSqMiles |
Incorporated Cities | 52 por_IncorporatedCities |
Number of Retail Customers | 844,393 por_NumberOfRetailCustomers |
Service Area Population | 1.8 por_ServiceAreaPopulation |
Percent of State's Population | 46.00%por_PercentOfStatesPopulation |
Other Comprehensive Income | $ 0 us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent | $ 0 us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent

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- Definition Number of incorporated cities in service area. + References No definition available. + Details
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- Definition Includes residential, commercial and industrial. + References No definition available. + Details
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- Definition Service area population as a percent of the state's population. + References No definition available. + Details
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- Definition Service Area Population + References No definition available. + Details
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- Definition Approximate square miles of service area. + References No definition available. + Details
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- Definition The increase (decrease) during the reporting period in the aggregate value of all inventory held by the reporting entity, associated with underlying transactions that are classified as operating activities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585 + Details
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