2.2.0.7 true NEWLY ADOPTED ACCOUNTING STANDARDS 110 - Disclosure - NEWLY ADOPTED ACCOUNTING STANDARDS 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/notestofinancialstatementsscheduleofnewaccountingpronouncementsandchangesinaccountingprinciplestextblock 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 NEWLY ADOPTED ACCOUNTING STANDARDS 2 us-gaap_ScheduleOfNewAccountingPronouncementsAndChangesInAccountingPrinciplesTextBlock 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> (3) NEWLY ADOPTED ACCOUNTING STANDARDS Transfers and Servicing (ASC 860) The FASB issued new guidance that removed the concept of a qualifying special-purpose entity (QSPE) from the guidance on transfers and servicing and the QSPE scope exception in the guidance on consolidation. The new guidance also changed the requirements for derecognizing financial assets and requires additional disclosures about a transferor’s continuing involvement in transferred financial assets. The guidance was effective for transfers of financial assets occurring in fiscal periods beginning on January 1, 2010 for PHI. As of January 1, 2010, PHI has adopted the provisions of this guidance and determined that the guidance did not have a material impact on its overall financial condition, results of operations, or cash flows.   Consolidation of Variable Interest Entities (ASC 810) The FASB issued new consolidation guidance regarding variable interest entities effective January 1, 2010 that eliminated the quantitative analysis requirement and added new qualitative factors to determine whether consolidation is required. The new qualitative factors are applied on a quarterly basis to interests in variable interest entities. Under the new guidance, the holder of the interest with the power to direct the most significant activities of the entity and the right to receive benefits or absorb losses significant to the entity would consolidate. The new guidance retained the provision that allows entities created before December 31, 2003 to be scoped out from a consolidation assessment if exhaustive efforts are taken and there is insufficient information to determine whether there is a relationship with a variable interest entity or the primary beneficiary of a variable interest entity. PHI has adopted the provisions of the new FASB guidance on consolidation of variable interest entities, and it did not have a material impact on its overall financial condition, results of operations, or cash flows. Fair Value Measurements and Disclosures (ASC 820) The FASB issued new disclosure requirements for recurring and non-recurring fair value measurements. The guidance, effective beginning with PHI’s March 31, 2010 financial statements, requires the disaggregation of balance sheet items measured at fair value into subsets of balance sheet items based on the nature and risks of the items. The standard requires descriptions of pricing inputs and valuation methodologies for instruments with Level 2 or 3 valuation inputs. In addition, the standard requires information about any transfers of instruments between Level 1 and 2 valuation categories. These additional disclosures can be found in Note (13), “Fair Value Disclosures.” Subsequent Events (ASC 855) The FASB issued new guidance which eliminated the requirement for PHI to disclose the date through which it has evaluated subsequent events beginning with its March 31, 2010 financial statements. </div> false false false us-types:textBlockItemType textblock Represents disclosure of any changes in an accounting principle, including a change from one generally accepted accounting principle to another generally accepted accounting principle when there are two or more generally accepted accounting principles that apply or when the accounting principle formerly used is no longer generally accepted. Also disclose any change in the method of applying an accounting principle, or any change in an accounting principle required by a new pronouncement in the unusual instance that a new pronouncement does not include specific transition provisions. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 154 -Paragraph 2, 17, 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 28 -Paragraph 23, 24 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 01 -Paragraph b -Subparagraph 6 -Article 10 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/notestofinancialstatementsscheduleofnewaccountingpronouncementsandchangesinaccountingprinciplestextblock 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 NEWLY ADOPTED ACCOUNTING STANDARDS 2 us-gaap_ScheduleOfNewAccountingPronouncementsAndChangesInAccountingPrinciplesTextBlock 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> (3) NEWLY ADOPTED ACCOUNTING STANDARDS Transfers and Servicing (Accounting Standards Codification (ASC) 860) The FASB issued new guidance that removed the concept of a qualifying special-purpose entity (QSPE) from the guidance on transfers and servicing and the QSPE scope exception in the guidance on consolidation. The new guidance also changed the requirements for derecognizing financial assets and requires additional disclosures about a transferor’s continuing involvement in transferred financial assets. The guidance was effective for transfers of financial assets occurring in fiscal periods beginning on January 1, 2010 for ACE. As of January 1, 2010, ACE has adopted the provisions of this guidance and determined that the guidance did not have a material impact on its overall financial condition, results of operations, or cash flows. Consolidation of Variable Interest Entities (ASC 810) The FASB issued new consolidation guidance regarding variable interest entities effective January 1, 2010 that eliminated the quantitative analysis requirement and added new qualitative factors to determine whether consolidation is required. The new qualitative factors are applied on a quarterly basis to interests in variable interest entities. Under the new guidance, the holder of the interest with the power to direct the most significant activities of the entity and the right to receive benefits or absorb losses significant to the entity would consolidate. The new guidance retained the provision that allows entities created before December 31, 2003 to be scoped out from a consolidation assessment if exhaustive efforts are taken and there is insufficient information to determine whether there is a relationship with a variable interest entity or the primary beneficiary of a variable interest entity. ACE has adopted the provisions of the new FASB guidance on consolidation of variable interest entities, and it did not have a material impact on its overall financial condition, results of operations, or cash flows. Fair Value Measurements and Disclosures (ASC 820) The FASB issued new disclosure requirements for recurring and non-recurring fair value measurements. The guidance, effective beginning with ACE’s March 31, 2010 financial statements, requires the disaggregation of balance sheet items measured at fair value into subsets of balance sheet items based on the nature and risks of the items. The standard requires descriptions of pricing inputs and valuation methodologies for instruments with Level 2 or 3 valuation inputs. In addition, the standard requires information about any transfers of instruments between Level 1 and 2 valuation categories. These additional disclosures can be found in Note (9), “Fair Value Disclosures.” Subsequent Events (ASC 855) The FASB issued new guidance which eliminated the requirement for ACE to disclose the date through which it has evaluated subsequent events beginning with its March 31, 2010 financial statements. </div> false false false us-types:textBlockItemType textblock Represents disclosure of any changes in an accounting principle, including a change from one generally accepted accounting principle to another generally accepted accounting principle when there are two or more generally accepted accounting principles that apply or when the accounting principle formerly used is no longer generally accepted. Also disclose any change in the method of applying an accounting principle, or any change in an accounting principle required by a new pronouncement in the unusual instance that a new pronouncement does not include specific transition provisions. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 154 -Paragraph 2, 17, 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 28 -Paragraph 23, 24 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 01 -Paragraph b -Subparagraph 6 -Article 10 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/notestofinancialstatementsscheduleofnewaccountingpronouncementsandchangesinaccountingprinciplestextblock 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 NEWLY ADOPTED ACCOUNTING STANDARDS 2 us-gaap_ScheduleOfNewAccountingPronouncementsAndChangesInAccountingPrinciplesTextBlock 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> (3) NEWLY ADOPTED ACCOUNTING STANDARDS Transfers and Servicing (ASC 860) The FASB issued new guidance that removed the concept of a qualifying special-purpose entity (QSPE) from the guidance on transfers and servicing and the QSPE scope exception in the guidance on consolidation. The new guidance also changed the requirements for derecognizing financial assets and requires additional disclosures about a transferor’s continuing involvement in transferred financial assets. The guidance was effective for transfers of financial assets occurring in fiscal periods beginning on January 1, 2010 for DPL. As of January 1, 2010, DPL has adopted the provisions of this guidance and determined that the guidance did not have a material impact on its overall financial condition, results of operations, or cash flows. Consolidation of Variable Interest Entities (ASC 810) The FASB issued new consolidation guidance regarding variable interest entities effective January 1, 2010 that eliminated the quantitative analysis requirement and added new qualitative factors to determine whether consolidation is required. The new qualitative factors are applied on a quarterly basis to interests in variable interest entities. Under the new guidance, the holder of the interest with the power to direct the most significant activities of the entity and the right to receive benefits or absorb losses significant to the entity would consolidate. The new guidance retained the provision that allows entities created before December 31, 2003 to be scoped out from a consolidation assessment if exhaustive efforts are taken and there is insufficient information to determine whether there is a relationship with a variable interest entity or the primary beneficiary of a variable interest entity. DPL has adopted the provisions of the new FASB guidance on consolidation of variable interest entities, and it did not have a material impact on its overall financial condition, results of operations, or cash flows. Fair Value Measurements and Disclosures (ASC 820) The FASB issued new disclosure requirements for recurring and non-recurring fair value measurements. The guidance, effective beginning with DPL’s March 31, 2010 financial statements, requires the disaggregation of balance sheet items measured at fair value into subsets of balance sheet items based on the nature and risks of the items. The standard requires descriptions of pricing inputs and valuation methodologies for instruments with Level 2 or 3 valuation inputs. In addition, the standard requires information about any transfers of instruments between Level 1 and 2 valuation categories. These additional disclosures can be found in Note (11), “Fair Value Disclosures.” Subsequent Events (ASC 855) The FASB issued new guidance which eliminated the requirement for DPL to disclose the date through which it has evaluated subsequent events beginning with its March 31, 2010 financial statements. </div> false false false us-types:textBlockItemType textblock Represents disclosure of any changes in an accounting principle, including a change from one generally accepted accounting principle to another generally accepted accounting principle when there are two or more generally accepted accounting principles that apply or when the accounting principle formerly used is no longer generally accepted. Also disclose any change in the method of applying an accounting principle, or any change in an accounting principle required by a new pronouncement in the unusual instance that a new pronouncement does not include specific transition provisions. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 154 -Paragraph 2, 17, 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 28 -Paragraph 23, 24 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 01 -Paragraph b -Subparagraph 6 -Article 10 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/notestofinancialstatementsscheduleofnewaccountingpronouncementsandchangesinaccountingprinciplestextblock 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 NEWLY ADOPTED ACCOUNTING STANDARDS 2 us-gaap_ScheduleOfNewAccountingPronouncementsAndChangesInAccountingPrinciplesTextBlock 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> (3) NEWLY ADOPTED ACCOUNTING STANDARDS Transfers and Servicing (Accounting Standards Codification (ASC) 860) The Financial Accounting Standards Board (FASB) issued new guidance that removed the concept of a qualifying special-purpose entity (QSPE) from the guidance on transfers and servicing and the QSPE scope exception in the guidance on consolidation. The new guidance also changed the requirements for derecognizing financial assets and requires additional disclosures about a transferor’s continuing involvement in transferred financial assets. The guidance was effective for transfers of financial assets occurring in fiscal periods beginning on January 1, 2010 for Pepco. As of January 1, 2010, Pepco has adopted the provisions of this guidance and determined that the guidance did not have a material impact on its overall financial condition, results of operations, or cash flows.   Consolidation of Variable Interest Entities (ASC 810) The FASB issued new consolidation guidance regarding variable interest entities effective January 1, 2010 that eliminated the quantitative analysis requirement and added new qualitative factors to determine whether consolidation is required. The new qualitative factors are applied on a quarterly basis to interests in variable interest entities. Under the new guidance, the holder of the interest with the power to direct the most significant activities of the entity and the right to receive benefits or absorb losses significant to the entity would consolidate. The new guidance retained the provision that allows entities created before December 31, 2003 to be scoped out from a consolidation assessment if exhaustive efforts are taken and there is insufficient information to determine whether there is a relationship with a variable interest entity or the primary beneficiary of a variable interest entity. Pepco has adopted the provisions of the new FASB guidance on consolidation of variable interest entities, and it did not have a material impact on its overall financial condition, results of operations, or cash flows. Fair Value Measurements and Disclosures (ASC 820) The FASB issued new disclosure requirements for recurring and non-recurring fair value measurements. The guidance, effective beginning with Pepco’s March 31, 2010 financial statements, requires the disaggregation of balance sheet items measured at fair value into subsets of balance sheet items based on the nature and risks of the items. The standard requires descriptions of pricing inputs and valuation methodologies for instruments with Level 2 or 3 valuation inputs. In addition, the standard requires information about any transfers of instruments between Level 1 and 2 valuation categories. These additional disclosures can be found in Note (9), “Fair Value Disclosures.” Subsequent Events (ASC 855) The FASB issued new guidance which eliminated the requirement for Pepco to disclose the date through which it has evaluated subsequent events beginning with its March 31, 2010 financial statements. </div> false false false us-types:textBlockItemType textblock Represents disclosure of any changes in an accounting principle, including a change from one generally accepted accounting principle to another generally accepted accounting principle when there are two or more generally accepted accounting principles that apply or when the accounting principle formerly used is no longer generally accepted. Also disclose any change in the method of applying an accounting principle, or any change in an accounting principle required by a new pronouncement in the unusual instance that a new pronouncement does not include specific transition provisions. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 154 -Paragraph 2, 17, 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 28 -Paragraph 23, 24 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 01 -Paragraph b -Subparagraph 6 -Article 10 false 1 8 false UnKnown UnKnown UnKnown false true