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Such costs could include business integration costs, systems integration and conversion costs, and severance and other employee-related costs.No definition available.false2Merger related costs3false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5false USDtruefalse$FROM_Apr01_2013_TO_Jun30_2013_dei_LegalEntityAxis_NevadaPowerCompanyMemberhttp://www.sec.gov/CIK0000741508duration2013-04-01T00:00:002013-06-30T00:00:00falsefalseNevada Power Company [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldinve_NevadaPowerCompanyMemberdei_LegalEntityAxisexplicitMemberUSDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Nevada Power Company [Member]4true 3nve_MergerRelatedActivitiesLineItemsnve_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Merger Related Activities [Line Items]5false 4us-gaap_BusinessCombinationIntegrationRelatedCostsus-gaap_truedebitdurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse88670008867000USD$falsefalsefalse2truefalsefalse00USD$falsefalsefalse3truefalsefalse88670008867000USD$falsefalsefalse4truefalsefalse00USD$falsefalsefalsexbrli:monetaryItemTypemonetaryCosts incurred to effect a business combination which have been expensed during the period. Such costs could include business integration costs, systems integration and conversion costs, and severance and other employee-related costs.No definition available.false2Merger related costs6false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse9false USDtruefalse$FROM_Apr01_2013_TO_Jun30_2013_dei_LegalEntityAxis_SierraPacificPowerCompanyMemberhttp://www.sec.gov/CIK0000741508duration2013-04-01T00:00:002013-06-30T00:00:00falsefalseSierra Pacific Power Company [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldinve_SierraPacificPowerCompanyMemberdei_LegalEntityAxisexplicitMemberUSDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0Sierra Pacific Power Company [Member]7true 3nve_MergerRelatedActivitiesLineItemsnve_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Merger Related Activities [Line Items]8false 4us-gaap_BusinessCombinationIntegrationRelatedCostsus-gaap_truedebitdurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse35200003520000USD$falsefalsefalse2truefalsefalse00USD$falsefalsefalse3truefalsefalse35200003520000USD$falsefalsefalse4truefalsefalse00USD$falsefalsefalsexbrli:monetaryItemTypemonetaryCosts incurred to effect a business combination which have been expensed during the period. Such costs could include business integration costs, systems integration and conversion costs, and severance and other employee-related costs.No definition available.false2Merger related costs9false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse13false USDtruefalse$FROM_Jan01_2013_TO_Jun30_2013_nve_MergerAxis_MidamericanMergerMemberhttp://www.sec.gov/CIK0000741508duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseMidAmerican Merger [Member]nve_MergerAxisxbrldihttp://xbrl.org/2006/xbrldinve_MidamericanMergerMembernve_MergerAxisexplicitMemberEPSDividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0USDollarStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$nanafalse0MidAmerican Merger [Member]10true 3nve_MergerRelatedActivitiesLineItemsnve_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Merger Related Activities [Line Items]11false 4nve_MergerAgreementDatenve_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00May 29, 2013falsefalsefalse4falsefalsefalse00falsefalsefalseinvest:dateStringItemTypenormalizedstringDate NVE entered into an agreement and plan of merger with MEHCNo definition available.false0Merger Agreement Date12false 4nve_ExpectedMergerClosingDatenve_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00first quarter of 2014falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringDate merger is expected to be completedNo definition available.false0Expected Merger Closing Date13false 4nve_MergerClosingConditionsnve_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00• the approval of the MidAmerican Merger by the holders of a majority of the outstanding shares of NVE common stock (NVE filed a preliminary proxy statement with the SEC in July 2013); • the receipt of regulatory approvals and other consents required to consummate the MidAmerican Merger, including, among others, approvals from the PUCN and the FERC on terms and conditions specified in the MidAmerican Merger Agreement (in July 2013, filings were made with the PUCN and FERC. See Note 4, Regulatory Actions, for further details of these filings); • the expiration or termination of the applicable waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976. On July 22, 2013, NVE was advised that the Department of Justice and the U.S. Federal Trade Commission had terminated the applicable waiting period under the Hart-Scott-Rodino Act. Consequently, the closing condition with respect to the Hart-Scott-Rodino Act has been satisfied; • the absence of the occurrence of a company material adverse effect (as defined in the MidAmerican Merger Agreement) after the date of the MidAmerican Merger Agreement; and • other customary closing conditions. falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringConditions required to be satisified before merger consummation.No definition available.false0Merger Closing Conditions14false 4nve_MergerTerminationRightnve_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00The MidAmerican Merger Agreement contains certain termination rights and fees for both NVE and MEHC. In the event of termination of the MidAmerican Merger under certain circumstances, NVE may be obligated to pay MEHC a termination fee of up to $169.7 million.falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringTermination rights with respect to the MidAmerican MergerNo definition available.false0Merger Termination Right15false 4nve_MergerTerminationFeenve_falsedebitinstantfalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse169700000169700000USD$falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse169700000169700000USD$falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryMerger Termination FeeNo definition available.false2Merger Termination Fee16false 4nve_MergerShareExchangeRationve_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse23.7523.75USD$falsetruefalse4falsefalsefalse00falsefalsefalsenum:perShareItemTypedecimalAmount of cash to be exchanged per shareNo definition available.false3Merger Share Exchange Ratio17false 4nve_FilingDateOfPreliminaryProxynve_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00July 2013falsefalsefalse4falsefalsefalse00falsefalsefalseinvest:dateStringItemTypenormalizedstringFiling date of prelimary proxyNo definition available.false0Filing Date of Preliminary Proxy18false 4nve_FilingDateOfPucnFilingnve_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00July 2013falsefalsefalse4falsefalsefalse00falsefalsefalseinvest:dateStringItemTypenormalizedstringFiling Date of PUCN filingNo definition available.false0Filing Date of PUCN filing19false 4nve_FilingDateOfFercFilingnve_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00July 2013falsefalsefalse4falsefalsefalse00falsefalsefalseinvest:dateStringItemTypenormalizedstringFiling Date of FERC filingNo definition available.false0Filing Date of FERC filing20false 4nve_SatisfactionDateOfHartScottRodinoConditionnve_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00July 22, 2013falsefalsefalse4falsefalsefalse00falsefalsefalseinvest:dateStringItemTypenormalizedstringSatisfaction date of the Hart-Scott Rodino ConditionNo definition available.false0Satisfaction date of Hart Scott Rodino Condition21false 4nve_ChangeOfControlDescriptionOfDebtnve_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00As a result, NVE, NPC and SPPC will be required to offer for purchase approximately $315.0 million, $3.1 billion, and $951.7 million, respectively, of debt at 101% of par within 10 days after the MidAmerican Merger closing.falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringDescription of Change of Control related to DebtNo definition available.false0Change of Control Description of Debt22false 4nve_MergerRestrictionsnve_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00The MidAmerican Merger Agreement contains customary representations, warranties and covenants for both NVE and MEHC. These covenants include an obligation for us, subject to certain exceptions, to conduct our business in a manner substantially consistent with our current practice. In addition, the covenants contain several restrictions that apply unless MEHC’s consent is received, including limitations on making certain business acquisitions, limitations on our total capital spending, limitations on the extent to which we may obtain financing through long-term debt or equity issuances or limitations on increasing our common stock dividend payout.falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringDescription of certain restrictions placed on the Company as a result of MidAmerican Merger, including among other items, the limitation of dividends, capital expenditures and theissuance of debt.No definition available.false0Merger Restrictions23false 4nve_MergerDescriptionnve_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00On May 29, 2013, NVE entered into the MidAmerican Merger Agreement. The MidAmerican Merger Agreement provides for the merger of Silver Merger Sub, Inc. with and into NVE, with NVE continuing as the surviving corporation in the MidAmerican Merger. Once merged, NVE will become an indirect wholly owned subsidiary of MEHC. 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