2.2.0.7 true PENSION AND OTHER POSTRETIREMENT BENEFITS 115 - Disclosure - PENSION AND OTHER POSTRETIREMENT BENEFITS 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/notestofinancialstatementspensionandotherpostretirementbenefitsdisclosuretextblock 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 PENSION AND OTHER POSTRETIREMENT BENEFITS 2 us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock us-gaap true na duration No definition available. false false false false false false false false false false false false 1 false false false false 0 0 <div> (8) PENSION AND OTHER POSTRETIREMENT BENEFITS The following Pepco Holdings information is for the three months ended September 30, 2010 and 2009:   <table border="0" cellspacing="0" cellpadding="0" width="100%" align="center"> <tr> <td width="80%"></td> <td valign="bottom" width="3%"></td> <td></td> <td></td> <td></td> <td valign="bottom" width="3%"></td> <td></td> <td></td> <td></td> <td valign="bottom" width="3%"></td> <td></td> <td></td> <td></td> <td valign="bottom" width="3%"></td> <td></td> <td></td> <td></td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom">  </td> <td style="BORDER-BOTTOM: #000000 1px solid" valign="bottom" colspan="6" align="center">Pension Benefits</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td style="BORDER-BOTTOM: #000000 1px solid" valign="bottom" colspan="6" align="center">Other Postretirement Benefits</td> <td valign="bottom"> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom">  </td> <td style="BORDER-BOTTOM: #000000 1px solid" valign="bottom" colspan="2" align="center">2010</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td style="BORDER-BOTTOM: #000000 1px solid" valign="bottom" colspan="2" align="center">2009</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td style="BORDER-BOTTOM: #000000 1px solid" valign="bottom" colspan="2" align="center">2010</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td style="BORDER-BOTTOM: #000000 1px solid" valign="bottom" colspan="2" align="center">2009</td> <td valign="bottom"> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom">  </td> <td valign="bottom" colspan="14" align="center">(millions of dollars)</td> <td valign="bottom"> </td> </tr> <tr bgcolor="#CCEEFF"> <td valign="top"> Service cost </td> <td valign="bottom">  </td> <td valign="bottom">$</td> <td valign="bottom" align="right">8</td> <td valign="bottom" nowrap="nowrap"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">9</td> <td valign="bottom" nowrap="nowrap"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">1</td> <td valign="bottom" nowrap="nowrap"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">2</td> <td valign="bottom" nowrap="nowrap"> </td> </tr> <tr> <td valign="top"> Interest cost </td> <td valign="bottom">  </td> <td valign="bottom"> </td> <td valign="bottom" align="right">28</td> <td valign="bottom" nowrap="nowrap"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">27</td> <td valign="bottom" nowrap="nowrap"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">10</td> <td valign="bottom" nowrap="nowrap"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">10</td> <td valign="bottom" nowrap="nowrap"> </td> </tr> <tr bgcolor="#CCEEFF"> <td valign="top"> Expected return on plan assets </td> <td valign="bottom">  </td> <td valign="bottom"> </td> <td valign="bottom" align="right">(30</td> <td valign="bottom" nowrap="nowrap">)</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">(25</td> <td valign="bottom" nowrap="nowrap">)</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">(4</td> <td valign="bottom" nowrap="nowrap">)</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">(3</td> <td valign="bottom" nowrap="nowrap">)</td> </tr> <tr> <td valign="top"> Amortization of prior service cost </td> <td valign="bottom">  </td> <td valign="bottom"> </td> <td valign="bottom" align="right">—  </td> <td valign="bottom" nowrap="nowrap">  </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">—  </td> <td valign="bottom" nowrap="nowrap">  </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">(1</td> <td valign="bottom" nowrap="nowrap">)</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">(1</td> <td valign="bottom" nowrap="nowrap">)</td> </tr> <tr bgcolor="#CCEEFF"> <td valign="top"> Amortization of net actuarial loss </td> <td valign="bottom">  </td> <td valign="bottom"> </td> <td valign="bottom" align="right">11</td> <td valign="bottom" nowrap="nowrap"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">14</td> <td valign="bottom" nowrap="nowrap"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">3</td> <td valign="bottom" nowrap="nowrap"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">3</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> <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> <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> <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> <td valign="top"> Net periodic benefit cost </td> <td valign="bottom">  </td> <td valign="bottom">$</td> <td valign="bottom" align="right">17</td> <td valign="bottom" nowrap="nowrap"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">25</td> <td valign="bottom" nowrap="nowrap"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">9</td> <td valign="bottom" nowrap="nowrap"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">11</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> <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> <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> <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> The following Pepco Holdings information is for the nine months ended September 30, 2010 and 2009:   <table border="0" cellspacing="0" cellpadding="0" width="100%" align="center"> <tr> <td width="80%"></td> <td valign="bottom" width="3%"></td> <td></td> <td></td> <td></td> <td valign="bottom" width="3%"></td> <td></td> <td></td> <td></td> <td valign="bottom" width="3%"></td> <td></td> <td></td> <td></td> <td valign="bottom" width="3%"></td> <td></td> <td></td> <td></td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom">  </td> <td style="BORDER-BOTTOM: #000000 1px solid" valign="bottom" colspan="6" align="center">Pension Benefits</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td style="BORDER-BOTTOM: #000000 1px solid" valign="bottom" colspan="6" align="center">Other  Postretirement Benefits</td> <td valign="bottom"> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom">  </td> <td style="BORDER-BOTTOM: #000000 1px solid" valign="bottom" colspan="2" align="center">2010</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td style="BORDER-BOTTOM: #000000 1px solid" valign="bottom" colspan="2" align="center">2009</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td style="BORDER-BOTTOM: #000000 1px solid" valign="bottom" colspan="2" align="center">2010</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td style="BORDER-BOTTOM: #000000 1px solid" valign="bottom" colspan="2" align="center">2009</td> <td valign="bottom"> </td> </tr> <tr> <td valign="bottom"> </td> <td valign="bottom">  </td> <td valign="bottom" colspan="14" align="center">(millions of dollars)</td> <td valign="bottom"> </td> </tr> <tr bgcolor="#CCEEFF"> <td valign="top"> Service cost </td> <td valign="bottom">  </td> <td valign="bottom">$</td> <td valign="bottom" align="right">26</td> <td valign="bottom" nowrap="nowrap"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">27</td> <td valign="bottom" nowrap="nowrap"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">4</td> <td valign="bottom" nowrap="nowrap"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">5</td> <td valign="bottom" nowrap="nowrap"> </td> </tr> <tr> <td valign="top"> Interest cost </td> <td valign="bottom">  </td> <td valign="bottom"> </td> <td valign="bottom" align="right">83</td> <td valign="bottom" nowrap="nowrap"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">83</td> <td valign="bottom" nowrap="nowrap"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">29</td> <td valign="bottom" nowrap="nowrap"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">30</td> <td valign="bottom" nowrap="nowrap"> </td> </tr> <tr bgcolor="#CCEEFF"> <td valign="top"> Expected return on plan assets </td> <td valign="bottom">  </td> <td valign="bottom"> </td> <td valign="bottom" align="right">(88</td> <td valign="bottom" nowrap="nowrap">)</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">(76</td> <td valign="bottom" nowrap="nowrap">)</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">(12</td> <td valign="bottom" nowrap="nowrap">)</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">(10</td> <td valign="bottom" nowrap="nowrap">)</td> </tr> <tr> <td valign="top"> Amortization of prior service cost </td> <td valign="bottom">  </td> <td valign="bottom"> </td> <td valign="bottom" align="right">—  </td> <td valign="bottom" nowrap="nowrap">  </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">—  </td> <td valign="bottom" nowrap="nowrap">  </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">(3</td> <td valign="bottom" nowrap="nowrap">)</td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">(3</td> <td valign="bottom" nowrap="nowrap">)</td> </tr> <tr bgcolor="#CCEEFF"> <td valign="top"> Amortization of net actuarial loss </td> <td valign="bottom">  </td> <td valign="bottom"> </td> <td valign="bottom" align="right">32</td> <td valign="bottom" nowrap="nowrap"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">43</td> <td valign="bottom" nowrap="nowrap"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">9</td> <td valign="bottom" nowrap="nowrap"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">12</td> <td valign="bottom" nowrap="nowrap"> </td> </tr> <tr> <td valign="top"> Plan amendment </td> <td valign="bottom">  </td> <td valign="bottom"> </td> <td valign="bottom" align="right">1</td> <td valign="bottom" nowrap="nowrap"> </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">—  </td> <td valign="bottom" nowrap="nowrap">  </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">—  </td> <td valign="bottom" nowrap="nowrap">  </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">—  </td> <td valign="bottom" nowrap="nowrap">  </td> </tr> <tr bgcolor="#CCEEFF"> <td valign="top"> Termination benefits </td> <td valign="bottom">  </td> <td valign="bottom"> </td> <td valign="bottom" align="right">—  </td> <td valign="bottom" nowrap="nowrap">  </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">—  </td> <td valign="bottom" nowrap="nowrap">  </td> <td valign="bottom"> </td> <td valign="bottom"> </td> <td valign="bottom" align="right">5</td> <td valign="bottom" nowrap="nowrap"> </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> <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> <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> <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> <td valign="top"> Net periodic benefit cost </td> <td valign="bottom">  </td> <td valign="bottom">$</td> <td valign="bottom" align="right">54</td> <td valign="bottom" nowrap="nowrap"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">77</td> <td valign="bottom" nowrap="nowrap"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">32</td> <td valign="bottom" nowrap="nowrap"> </td> <td valign="bottom"> </td> <td valign="bottom">$</td> <td valign="bottom" align="right">34</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> <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> <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> <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>   Pension and Other Postretirement Benefits Net periodic benefit cost related to continuing operations is included in other Operation and Maintenance expense, net of the portion of the net periodic benefit cost that is capitalized as part of the cost of labor for internal construction projects. PHI’s pension and other postretirement net periodic benefit costs for the nine months ended September 30, 2010 includes a one time charge of $6 million related to the sale of Conectiv Energy which is reflected in net loss from discontinued operations. After intercompany allocations, the three utility subsidiaries are responsible for substantially all of the total PHI net periodic pension and other postretirement benefit costs related to continuing operations. Pension Contributions PHI’s funding policy with regard to PHI’s noncontributory retirement plan (the PHI Retirement Plan) is to maintain a funding level that is at least equal to the funding target level under the Pension Protection Act of 2006. Although PHI currently has no minimum funding requirement under the Pension Protection Act guidelines in 2010, PHI Service Company has made discretionary tax-deductible contributions to the PHI Retirement Plan of $35 million on each of July 1, 2010 and August 2, 2010, and $30 million on September 1, 2010. These contributions in the aggregate amount of $100 million brought the PHI Retirement Plan assets to the funding target level for 2010 under the Pension Protection Act. During 2009, discretionary tax-deductible contributions totaling $300 million were made to the PHI Retirement Plan which brought plan assets to at least the funding target level for 2009 under the Pension Protection Act. Of this amount, $240 million consisted of tax-deductible contributions made by Pepco, ACE and DPL in the amounts of $170 million, $60 million and $10 million, respectively. The remaining $60 million consisted of tax-deductible contributions made by the PHI Service Company. </div> false false false us-types:textBlockItemType textblock Description containing the entire pension and other postretirement benefits disclosure as a single block of text. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FAS106-2 -Paragraph 20, 21, 22 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5, 6, 7, 8 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 87 -Paragraph 264 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Implementation Guide (Q and A) -Number FAS88 -Paragraph 63 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 158 -Paragraph 7, 21, 22 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph b Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 30 -Paragraph 26 Reference 8: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 106 -Paragraph 518 Reference 9: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 03-2 -Paragraph 8 Reference 10: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 8 -Subparagraph m Reference 11: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph h Reference 12: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph a Reference 13: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph q false 3 ATLANTIC CITY ELECTRIC CO 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/notestofinancialstatementspensionandotherpostretirementbenefitsdisclosuretextblock false 1 false false false false 0 0 false false false false 2 USD true false false false ATLANTIC CITY ELECTRIC CO dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi pom_AtlanticCityElectricCoMember 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 PENSION AND OTHER POSTRETIREMENT BENEFITS 2 us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock us-gaap true na duration No definition available. false false false false false false false false false false false false 1 false false false false 0 0 <div> (6) PENSION AND OTHER POSTRETIREMENT BENEFITS ACE accounts for its participation in the Pepco Holdings benefit plans as participation in a multi-employer plan. PHI’s pension and other postretirement net periodic benefit cost for the three months ended September 30, 2010 and 2009, before intercompany allocations from the PHI Service Company, of $26 million and $36 million, respectively, included $6 million and $5 million, respectively, for ACE’s allocated share. PHI’s pension and other postretirement net periodic benefit cost for the nine months ended September 30, 2010 and 2009, before intercompany allocations from the PHI Service Company, of $86 million and $111 million, respectively, included $17 million and $15 million, respectively, for ACE’s allocated share. </div> false false false us-types:textBlockItemType textblock Description containing the entire pension and other postretirement benefits disclosure as a single block of text. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FAS106-2 -Paragraph 20, 21, 22 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5, 6, 7, 8 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 87 -Paragraph 264 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Implementation Guide (Q and A) -Number FAS88 -Paragraph 63 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 158 -Paragraph 7, 21, 22 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph b Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 30 -Paragraph 26 Reference 8: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 106 -Paragraph 518 Reference 9: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 03-2 -Paragraph 8 Reference 10: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 8 -Subparagraph m Reference 11: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph h Reference 12: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph a Reference 13: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph q false 5 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/notestofinancialstatementspensionandotherpostretirementbenefitsdisclosuretextblock false 1 false false false false 0 0 false false false false 3 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 6 PENSION AND OTHER POSTRETIREMENT BENEFITS 2 us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock us-gaap true na duration No definition available. false false false false false false false false false false false false 1 false false false false 0 0 <div> (7) PENSION AND OTHER POSTRETIREMENT BENEFITS DPL accounts for its participation in the Pepco Holdings benefit plans as participation in a multi-employer plan. PHI’s pension and other postretirement net periodic benefit cost for the three months ended September 30, 2010 and 2009, before intercompany allocations from the PHI Service Company, of $26 million and $36 million, respectively, included $7 million and $6 million, respectively, for DPL’s allocated share. PHI’s pension and other postretirement net periodic benefit cost for the nine months ended September 30, 2010 and 2009, before intercompany allocations from the PHI Service Company, of $86 million and $111 million, respectively, included $21 million and $19 million, respectively, for DPL’s allocated share. </div> false false false us-types:textBlockItemType textblock Description containing the entire pension and other postretirement benefits disclosure as a single block of text. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FAS106-2 -Paragraph 20, 21, 22 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5, 6, 7, 8 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 87 -Paragraph 264 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Implementation Guide (Q and A) -Number FAS88 -Paragraph 63 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 158 -Paragraph 7, 21, 22 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph b Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 30 -Paragraph 26 Reference 8: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 106 -Paragraph 518 Reference 9: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 03-2 -Paragraph 8 Reference 10: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 8 -Subparagraph m Reference 11: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph h Reference 12: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph a Reference 13: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph q false 7 POTOMAC ELECTRIC POWER CO 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/notestofinancialstatementspensionandotherpostretirementbenefitsdisclosuretextblock false 1 false false false false 0 0 false false false false 4 USD true false false false POTOMAC ELECTRIC POWER CO dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi pom_PotomacElectricPowerCoMember dei_LegalEntityAxis explicitMember iso4217_USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ na No definition available. No authoritative reference available. false 8 PENSION AND OTHER POSTRETIREMENT BENEFITS 2 us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock us-gaap true na duration No definition available. false false false false false false false false false false false false 1 false false false false 0 0 <div> (6) PENSION AND OTHER POSTRETIREMENT BENEFITS Pepco accounts for its participation in the Pepco Holdings benefit plans as participation in a multi-employer plan. PHI’s pension and other postretirement net periodic benefit cost for the three months ended September 30, 2010 and 2009, before intercompany allocations from the PHI Service Company, of $26 million and $36 million, respectively, included $10 million and $9 million, respectively, for Pepco’s allocated share. PHI’s pension and other postretirement net periodic benefit cost for the nine months ended September 30, 2010 and 2009, before intercompany allocations from the PHI Service Company, of $86 million and $111 million, respectively, included $30 million and $28 million, respectively, for Pepco’s allocated share. </div> false false false us-types:textBlockItemType textblock Description containing the entire pension and other postretirement benefits disclosure as a single block of text. 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