2.2.0.7 true GOODWILL 113 - Disclosure - GOODWILL true false false false 1 USD true false false false PEPCO HOLDINGS INC dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_ParentCompanyMember dei_LegalEntityAxis explicitMember iso4217_USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 iso4217_USD_per_shares Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares 0 shares Standard http://www.xbrl.org/2003/instance shares 0 $ 1 PEPCO HOLDINGS INC 0 na true na na No definition available. false true false false false false false false false false false http://www.pepcoholdings.com/taxonomy/role/notestofinancialstatementsgoodwilldisclosuretextblock false 1 false false false false 0 0 false false false false 1 USD true false false false PEPCO HOLDINGS INC dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_ParentCompanyMember dei_LegalEntityAxis explicitMember iso4217_USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 iso4217_USD_per_shares Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares 0 shares Standard http://www.xbrl.org/2003/instance shares 0 $ na No definition available. No authoritative reference available. false 2 GOODWILL 2 pom_GoodwillDisclosureTextBlock pom false na duration This block of text may be used to disclose all or part of the information related to goodwill. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 <div> (6) GOODWILL PHI’s goodwill balance of $1.4 billion was unchanged during the three and nine months ended September 30, 2010. Substantially all of PHI’s $1.4 billion goodwill balance was generated by Pepco’s acquisition of Conectiv in 2002 and is allocated entirely to the Power Delivery reporting unit based on the aggregation of its regulated public utility company components for purposes of assessing impairment under FASB guidance on goodwill and other intangibles (ASC 350). PHI’s annual impairment tests as of July 1, 2009 and November 1, 2009 indicated that goodwill was not impaired. As of September 30, 2010, after review of its significant assumptions in the goodwill impairment analysis, PHI concluded that there were no events requiring it to perform an interim goodwill impairment test. Although PHI’s market capitalization was below book value at September 30, 2010, PHI’s market capitalization has improved compared to earlier periods when it performed interim impairment tests. PHI performed its previous annual goodwill impairment tests as of November 1, 2009 and July 1, 2009, and an interim impairment test as of March 31, 2009 when its market capitalization was further below book value than at September 30, 2010, and concluded that its goodwill was not impaired at those earlier dates. PHI will continue to closely monitor for indicators of goodwill impairment, including the sustained period of time that PHI’s stock price has been below its book value. A roll forward of PHI’s goodwill balance is set forth below in millions of dollars:   <table border="0" cellspacing="0" cellpadding="0" width="100%" align="center"> <tr> <td width="94%"></td> <td valign="bottom" width="2%"></td> <td></td> <td></td> <td></td> </tr> <tr bgcolor="#CCEEFF"> <td valign="top"> Balance, December 31, 2008 </td> <td valign="bottom">  </td> <td valign="bottom">$</td> <td valign="bottom" align="right">1,411</td> <td valign="bottom" nowrap="nowrap">  </td> </tr> <tr> <td valign="top"> Less: Impairment charge associated with the wind-down of Pepco Energy Services retail energy business </td> <td valign="bottom">  </td> <td valign="bottom"> </td> <td valign="bottom" align="right">(4</td> <td valign="bottom" nowrap="nowrap">)</td> </tr> <tr style="FONT-SIZE: 1px"> <td valign="bottom"></td> <td valign="bottom">  </td> <td style="BORDER-TOP: #000000 1px solid" valign="bottom">  </td> <td style="BORDER-TOP: #000000 1px solid" valign="bottom">  </td> <td> </td> </tr> <tr bgcolor="#CCEEFF"> <td valign="top"> Balance, December 31, 2009 </td> <td valign="bottom">  </td> <td valign="bottom"> </td> <td valign="bottom" align="right">1,407</td> <td valign="bottom" nowrap="nowrap">  </td> </tr> <tr> <td valign="top"> Less: Adjustments </td> <td valign="bottom">  </td> <td valign="bottom"> </td> <td valign="bottom" align="right">—  </td> <td valign="bottom" nowrap="nowrap">  </td> </tr> <tr style="FONT-SIZE: 1px"> <td valign="bottom"></td> <td valign="bottom">  </td> <td style="BORDER-TOP: #000000 1px solid" valign="bottom">  </td> <td style="BORDER-TOP: #000000 1px solid" valign="bottom">  </td> <td> </td> </tr> <tr bgcolor="#CCEEFF"> <td valign="top"> Balance, September 30, 2010 </td> <td valign="bottom">  </td> <td valign="bottom">$</td> <td valign="bottom" align="right">1,407</td> <td valign="bottom" nowrap="nowrap">  </td> </tr> <tr style="FONT-SIZE: 1px"> <td valign="bottom"></td> <td valign="bottom">  </td> <td style="BORDER-TOP: #000000 3px double" valign="bottom">  </td> <td style="BORDER-TOP: #000000 3px double" valign="bottom">  </td> <td> </td> </tr> </table> </div> false false false us-types:textBlockItemType textblock This block of text may be used to disclose all or part of the information related to goodwill. No authoritative reference available. false 3 DELMARVA POWER & LIGHT CO /DE/ 0 na true na na No definition available. false true false false false false false false false false false http://www.pepcoholdings.com/taxonomy/role/notestofinancialstatementsgoodwilldisclosuretextblock false 1 false false false false 0 0 false false false false 2 USD true false false false DELMARVA POWER & LIGHT CO /DE/ dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi pom_DelmarvaPowerLightCoMember dei_LegalEntityAxis explicitMember iso4217_USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ na No definition available. No authoritative reference available. false 4 GOODWILL 2 pom_GoodwillDisclosureTextBlock pom false na duration This block of text may be used to disclose all or part of the information related to goodwill. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 <div> (6) GOODWILL DPL’s goodwill balance of $8 million was unchanged during the three and nine month periods ending September 30, 2010. All of DPL’s goodwill was generated by its acquisition of Conowingo Power Company in 1995. DPL’s annual impairment tests as of July 1, 2009 and November 1, 2009 indicated that goodwill was not impaired. As of September 30, 2010, after review of its significant assumptions in the goodwill impairment analysis, DPL concluded that there were no events requiring it to perform an interim goodwill impairment test. DPL will continue to closely monitor for indicators of goodwill impairment. </div> false false false us-types:textBlockItemType textblock This block of text may be used to disclose all or part of the information related to goodwill. No authoritative reference available. false 1 4 false UnKnown UnKnown UnKnown false true