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Basis of Presentation (Details) (USD $) Share data in Millions, unless otherwise specified | 3 Months Ended
--- | ---
Mar. 31, 2014 sqmi retail_customers | Mar. 31, 2013
Basis of Presentation [Abstract] |  |
Service Area Sq Miles | 4,000 |
Incorporated Cities | 52 |
Number of Retail Customers | 838,283 |
Service Area Population | 1.7 |
Percent of State's Population | 44.00% |
Cash received to be returned to customers pursuant to the Residential Exchange Program | $ 15,000,000 | $ 2,000,000
Power Cost Deferrals, Net |  | 2,000,000
Other Comprehensive Income | $ 0 | $ 0

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- Definition Costs of power used for operations in prior periods that were expected to be recovered from customers in future periods. + 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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