2.4.0.82401404 - Disclosure - Summary of Significant Accounting Policies Asset Retirement Obligations (Details)truefalseIn Millions, unless otherwise specifiedfalse1false USDfalsefalse$D2013Q2YTDhttp://www.sec.gov/CIK0000074145duration2013-01-01T00:00:002013-06-30T00:00:00usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$2false USDfalsefalse$D2012Q2YTDhttp://www.sec.gov/CIK0000074145duration2012-01-01T00:00:002012-06-30T00:00:00usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$1true 4us-gaap_AssetRetirementObligationRollForwardAnalysisRollForwardus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]2false 5us-gaap_AssetRetirementObligationus-gaap_truecreditinstantfalsefalsefalsefalsefalsetruefalsefalseperiodStartLabel1truefalsefalse5360000053.6USD$falsetruefalse2truefalsefalse2480000024.8USD$falsetruefalsexbrli:monetaryItemTypemonetaryThe carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Asset Retirement Obligation -URI http://asc.fasb.org/extlink&oid=6505190 false2Balance at January 13false 5us-gaap_AssetRetirementObligationLiabilitiesSettledus-gaap_truedebitdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse00falsefalsefalse2truefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryAmount of asset retirement obligations settled, or otherwise disposed of, during the period. This may include asset retirement obligations transferred to third parties associated with the sale of a long-lived asset.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849 false2Liabilities settled4false 5us-gaap_AssetRetirementObligationAccretionExpenseus-gaap_truedebitdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse11000001.1falsefalsefalse2truefalsefalse9000000.9falsefalsefalsexbrli:monetaryItemTypemonetaryAmount of accretion expense recognized during the period that is associated with an asset retirement obligation. Accretion expense measures and incorporates changes due to the passage of time into the carrying amount of the liability.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6392676&loc=d3e7480-110848 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c)(3) -URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849 false2Accretion expense5false 5us-gaap_AssetRetirementObligationRevisionOfEstimateus-gaap_truecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse00falsefalsefalse2truefalsefalse2670000026.7[1]falsefalsefalsexbrli:monetaryItemTypemonetaryAmount of the Increase or Decrease in the amount of the asset retirement obligation during the current period for changes in the amount or timing of the estimated cash flows associated with the settlement of the obligation.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c)(4) -URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849 false2Revisions in estimated cash flows6false 5us-gaap_AssetRetirementObligationus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsetruefalseperiodEndLabel1truefalsefalse5470000054.7USD$falsetruefalse2truefalsefalse5240000052.4USD$falsetruefalsexbrli:monetaryItemTypemonetaryThe carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Asset Retirement Obligation -URI http://asc.fasb.org/extlink&oid=6505190 false2Balance at June 301Due to changes to OG&E's asset retirement obligations related to its wind farms as a result of changes in the assumption related to the timing of removal used in the valuation of the asset retirement obligations.falseSummary of Significant Accounting Policies Asset Retirement Obligations (Details) (USD $)HundredThousandsUnKnownUnKnownUnKnowntruefalsefalseSheethttp://www.oge.com/role/SummaryOfSignificantAccountingPoliciesAssetRetirementObligationsDetails26