1.0.0.3 true Statement Of Financial Position Classified (USD $) In Millions false 1 $ true false false false us-gaap_ParentCompanyMember dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_ParentCompanyMember dei_LegalEntityAxis explicitMember Shares Standard http://www.xbrl.org/2003/instance shares 0 USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 USDperShareItemType Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares 0 false 2 $ true false false false us-gaap_ParentCompanyMember dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_ParentCompanyMember dei_LegalEntityAxis explicitMember Shares Standard http://www.xbrl.org/2003/instance shares 0 USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 USDperShareItemType Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares 0 1 PEPCO HOLDINGS INC 0 na true na na na No definition available. false true false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. No authoritative reference available. false 2 CURRENT ASSETS 2 us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 3 Cash and cash equivalents 2 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 true true 120000000 120 false false 2 true true 384000000 384 false false No definition available. No authoritative reference available. false 4 Restricted cash equivalents 2 us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 9000000 9 false false 2 false true 10000000 10 false false No definition available. No authoritative reference available. false 5 Accounts receivable, less allowance for uncollectible accounts 2 us-gaap_AccountsReceivableNetCurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 1158000000 1158 false false 2 false true 1392000000 1392 false false No definition available. No authoritative reference available. false 6 Inventories 2 us-gaap_InventoryNet us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 282000000 282 false false 2 false true 333000000 333 false false No definition available. No authoritative reference available. false 7 Derivative assets 2 us-gaap_DerivativeAssetsCurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 83000000 83 false false 2 false true 98000000 98 false false No definition available. No authoritative reference available. false 8 Prepayments of income taxes 2 us-gaap_PrepaidTaxes us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 238000000 238 false false 2 false true 294000000 294 false false No definition available. No authoritative reference available. false 9 Prepaid expenses and other 2 us-gaap_OtherAssetsCurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 165000000 165 false false 2 false true 115000000 115 false false No definition available. No authoritative reference available. false 10 Total Current Assets 2 us-gaap_AssetsCurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 2055000000 2055 false false 2 false true 2626000000 2626 false false No definition available. No authoritative reference available. true 11 INVESTMENTS AND OTHER ASSETS 2 pom false na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 12 Goodwill 2 us-gaap_Goodwill us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 1411000000 1411 false false 2 false true 1411000000 1411 false false No definition available. No authoritative reference available. false 13 Regulatory assets 2 us-gaap_RegulatoryAssetsNoncurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 1993000000 1993 false false 2 false true 2088000000 2088 false false No definition available. No authoritative reference available. false 16 Investment in finance leases held in trust 2 us-gaap_AssetsHeldInTrustNoncurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 1362000000 1362 false false 2 false true 1335000000 1335 false false No definition available. No authoritative reference available. false 17 Income taxes receivable 2 pom_IncomeTaxesReceivableNoncurrent pom false debit instant monetary No definition available. false false false false false false false false false 1 false true 314000000 314 false false 2 false true 191000000 191 false false No definition available. No authoritative reference available. false 18 Restricted cash equivalents 2 us-gaap_RestrictedCashAndCashEquivalentsNoncurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 69000000 69 false false 2 false true 108000000 108 false false No definition available. No authoritative reference available. false 19 Assets and accrued interest related to uncertain tax positions 2 pom_AssetsAndAccruedInterestRelatedToUncertainTaxPositionsNoncurrent pom false debit instant monetary No definition available. false false false false false false false false false 1 false true 115000000 115 false false 2 false true 178000000 178 false false No definition available. No authoritative reference available. false 20 Derivative assets 2 us-gaap_DerivativeAssetsNoncurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 29000000 29 false false 2 false true 9000000 9 false false No definition available. No authoritative reference available. false 21 Other 2 us-gaap_OtherAssetsNoncurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 204000000 204 false false 2 false true 215000000 215 false false No definition available. No authoritative reference available. false 22 Total Investments and Other Assets 2 pom_TotalInvestmentsAndOtherAssets pom false debit instant monetary No definition available. false false false false false false false false false 1 false true 5497000000 5497 false false 2 false true 5535000000 5535 false false No definition available. No authoritative reference available. true 23 PROPERTY, PLANT AND EQUIPMENT 2 us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 24 Property, plant and equipment 2 us-gaap_PropertyPlantAndEquipmentGross us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 13298000000 13298 false false 2 false true 12926000000 12926 false false No definition available. No authoritative reference available. false 25 Accumulated depreciation 2 us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true -4737000000 -4737 false false 2 false true -4612000000 -4612 false false No definition available. No authoritative reference available. false 26 Net Property, Plant and Equipment 2 us-gaap_PropertyPlantAndEquipmentNet us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 8561000000 8561 false false 2 false true 8314000000 8314 false false No definition available. No authoritative reference available. true 27 TOTAL ASSETS 2 us-gaap_Assets us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 16113000000 16113 false false 2 false true 16475000000 16475 false false No definition available. No authoritative reference available. true 28 CURRENT LIABILITIES 2 us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 29 Short-term debt 2 us-gaap_ShortTermBorrowings us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 640000000 640 false false 2 false true 465000000 465 false false No definition available. No authoritative reference available. false 30 Current maturities of long-term debt 2 us-gaap_LongTermDebtCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 502000000 502 false false 2 false true 85000000 85 false false No definition available. No authoritative reference available. false 31 Accounts payable and accrued liabilities 2 us-gaap_AccountsPayableAndAccruedLiabilities us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 658000000 658 false false 2 false true 847000000 847 false false No definition available. No authoritative reference available. false 33 Capital lease obligations due within one year 2 us-gaap_CapitalLeaseObligationsCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 7000000 7 false false 2 false true 6000000 6 false false No definition available. No authoritative reference available. false 34 Taxes accrued 2 us-gaap_TaxesPayable us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 62000000 62 false false 2 false true 62000000 62 false false No definition available. No authoritative reference available. false 35 Interest accrued 2 us-gaap_InterestPayable us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 69000000 69 false false 2 false true 71000000 71 false false No definition available. No authoritative reference available. false 36 Liabilities and accrued interest related to uncertain tax positions 2 us-gaap_LiabilityForUncertainTaxPositionsCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 4000000 4 false false 2 false true 71000000 71 false false No definition available. No authoritative reference available. false 37 Derivative liabilities 2 us-gaap_DerivativeLiabilitiesCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 138000000 138 false false 2 false true 144000000 144 false false No definition available. No authoritative reference available. false 38 Other 2 us-gaap_OtherLiabilitiesCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 302000000 302 false false 2 false true 279000000 279 false false No definition available. No authoritative reference available. false 39 Total Current Liabilities 2 us-gaap_LiabilitiesCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 2382000000 2382 false false 2 false true 2030000000 2030 false false No definition available. No authoritative reference available. true 40 DEFERRED CREDITS 2 pom false na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 41 Regulatory liabilities 2 us-gaap_RegulatoryLiabilityNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 754000000 754 false false 2 false true 893000000 893 false false No definition available. No authoritative reference available. false 42 Deferred income taxes, net 2 us-gaap_DeferredTaxLiabilitiesNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 2306000000 2306 false false 2 false true 2269000000 2269 false false No definition available. No authoritative reference available. false 43 Investment tax credits 2 us-gaap_AccumulatedDeferredInvestmentTaxCredit us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 38000000 38 false false 2 false true 40000000 40 false false No definition available. No authoritative reference available. false 45 Pension benefit obligation 2 us-gaap_DefinedBenefitPensionPlanNoncurrentLiabilities us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 469000000 469 false false 2 false true 626000000 626 false false No definition available. No authoritative reference available. false 46 Other postretirement benefit obligation 2 us-gaap_OtherPostretirementDefinedBenefitPlanNoncurrentLiabilities us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 447000000 447 false false 2 false true 461000000 461 false false No definition available. No authoritative reference available. false 47 Income taxes payable 2 pom_IncomeTaxesPayableNoncurrent pom false credit instant monetary No definition available. false false false false false false false false false 1 false true 186000000 186 false false 2 false true 176000000 176 false false No definition available. No authoritative reference available. false 48 Liabilities and accrued interest related to uncertain tax positions 2 us-gaap_LiabilityForUncertainTaxPositionsNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 175000000 175 false false 2 false true 163000000 163 false false No definition available. No authoritative reference available. false 49 Derivative liabilities 2 us-gaap_DerivativeLiabilitiesNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 79000000 79 false false 2 false true 59000000 59 false false No definition available. No authoritative reference available. false 50 Other 2 us-gaap_OtherLiabilitiesNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 151000000 151 false false 2 false true 184000000 184 false false No definition available. No authoritative reference available. false 51 Total Deferred Credits 2 pom_TotalDeferredCreditsAndOtherLiabilities pom false credit instant monetary No definition available. false false false false false false false false false 1 false true 4605000000 4605 false false 2 false true 4871000000 4871 false false No definition available. No authoritative reference available. true 52 LONG-TERM LIABILITIES 2 pom false na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 53 Long-term debt 2 us-gaap_LongTermDebtNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 4502000000 4502 false false 2 false true 4859000000 4859 false false No definition available. No authoritative reference available. false 54 Transition bonds issued by ACE Funding 2 us-gaap_LongTermTransitionBond us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 385000000 385 false false 2 false true 401000000 401 false false No definition available. No authoritative reference available. false 55 Long-term project funding 2 us-gaap_OtherLongTermDebtNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 18000000 18 false false 2 false true 19000000 19 false false No definition available. No authoritative reference available. false 56 Capital lease obligations 2 us-gaap_CapitalLeaseObligationsNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 96000000 96 false false 2 false true 99000000 99 false false No definition available. No authoritative reference available. false 57 Total Long-Term Liabilities 2 us-gaap_LongTermDebtAndCapitalLeaseObligations us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 5001000000 5001 false false 2 false true 5378000000 5378 false false No definition available. No authoritative reference available. true 59 COMMITMENTS AND CONTINGENCIES 2 us-gaap_CommitmentsAndContingencies us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 0 0 false false 2 false true 0 0 false false No definition available. No authoritative reference available. false 61 EQUITY 2 pom false na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 62 Common stock 2 us-gaap_CommonStockValue us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 2000000 2 false false 2 false true 2000000 2 false false No definition available. No authoritative reference available. false 63 Premium on stock and other capital contributions 2 us-gaap_AdditionalPaidInCapitalCommonStock us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 3203000000 3203 false false 2 false true 3179000000 3179 false false No definition available. No authoritative reference available. false 64 Accumulated other comprehensive loss 2 us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true -308000000 -308 false false 2 false true -262000000 -262 false false No definition available. No authoritative reference available. false 65 Retained earnings 2 us-gaap_RetainedEarningsAccumulatedDeficit us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 1222000000 1222 false false 2 false true 1271000000 1271 false false No definition available. No authoritative reference available. false 66 Total Equity 2 us-gaap_StockholdersEquity us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 4119000000 4119 false false 2 false true 4190000000 4190 false false No definition available. No authoritative reference available. true 67 Noncontrolling interest 2 us-gaap_MinorityInterest us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 6000000 6 false false 2 false true 6000000 6 false false No definition available. No authoritative reference available. false 68 Total Equity 2 pom_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest pom false credit instant monetary No definition available. false false false false false false false false false 1 false true 4125000000 4125 false false 2 false true 4196000000 4196 false false No definition available. No authoritative reference available. true 69 TOTAL LIABILITIES AND EQUITY 2 us-gaap_LiabilitiesAndStockholdersEquity us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 16113000000 16113 false false 2 false true 16475000000 16475 false false No definition available. No authoritative reference available. true 70 POTOMAC ELECTRIC POWER CO 0 na true na na na No definition available. false true false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. No authoritative reference available. false 71 CURRENT ASSETS 2 us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 72 Cash and cash equivalents 2 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 69000000 69 false false 2 false true 146000000 146 false false No definition available. No authoritative reference available. false 74 Accounts receivable, less allowance for uncollectible accounts 2 us-gaap_AccountsReceivableNetCurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 359000000 359 false false 2 false true 377000000 377 false false No definition available. No authoritative reference available. false 75 Inventories 2 us-gaap_InventoryNet us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 46000000 46 false false 2 false true 45000000 45 false false No definition available. No authoritative reference available. false 77 Prepayments of income taxes 2 us-gaap_PrepaidTaxes us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 67000000 67 false false 2 false true 151000000 151 false false No definition available. No authoritative reference available. false 78 Prepaid expenses and other 2 us-gaap_OtherAssetsCurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 22000000 22 false false 2 false true 37000000 37 false false No definition available. No authoritative reference available. false 79 Total Current Assets 2 us-gaap_AssetsCurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 563000000 563 false false 2 false true 756000000 756 false false No definition available. No authoritative reference available. true 80 INVESTMENTS AND OTHER ASSETS 2 pom false na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 82 Regulatory assets 2 us-gaap_RegulatoryAssetsNoncurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 154000000 154 false false 2 false true 169000000 169 false false No definition available. No authoritative reference available. false 83 Prepaid pension expense 2 us-gaap_PrepaidPensionCosts us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 280000000 280 false false 2 false true 142000000 142 false false No definition available. No authoritative reference available. false 84 Investment in trust 2 us-gaap_DeferredCompensationPlanAssets us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 24000000 24 false false 2 false true 24000000 24 false false No definition available. No authoritative reference available. false 86 Income taxes receivable 2 pom_IncomeTaxesReceivableNoncurrent pom false debit instant monetary No definition available. false false false false false false false false false 1 false true 194000000 194 false false 2 false true 166000000 166 false false No definition available. No authoritative reference available. false 87 Restricted cash equivalents 2 us-gaap_RestrictedCashAndCashEquivalentsNoncurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 64000000 64 false false 2 false true 102000000 102 false false No definition available. No authoritative reference available. false 88 Assets and accrued interest related to uncertain tax positions 2 pom_AssetsAndAccruedInterestRelatedToUncertainTaxPositionsNoncurrent pom false debit instant monetary No definition available. false false false false false false false false false 1 false true 4000000 4 false false 2 false true 35000000 35 false false No definition available. No authoritative reference available. false 90 Other 2 us-gaap_OtherAssetsNoncurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 72000000 72 false false 2 false true 70000000 70 false false No definition available. No authoritative reference available. false 91 Total Investments and Other Assets 2 pom_TotalInvestmentsAndOtherAssets pom false debit instant monetary No definition available. false false false false false false false false false 1 false true 792000000 792 false false 2 false true 708000000 708 false false No definition available. No authoritative reference available. true 92 PROPERTY, PLANT AND EQUIPMENT 2 us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 93 Property, plant and equipment 2 us-gaap_PropertyPlantAndEquipmentGross us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 5726000000 5726 false false 2 false true 5607000000 5607 false false No definition available. No authoritative reference available. false 94 Accumulated depreciation 2 us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true -2428000000 -2428 false false 2 false true -2371000000 -2371 false false No definition available. No authoritative reference available. false 95 Net Property, Plant and Equipment 2 us-gaap_PropertyPlantAndEquipmentNet us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 3298000000 3298 false false 2 false true 3236000000 3236 false false No definition available. No authoritative reference available. true 96 TOTAL ASSETS 2 us-gaap_Assets us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 4653000000 4653 false false 2 false true 4700000000 4700 false false No definition available. No authoritative reference available. true 97 CURRENT LIABILITIES 2 us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 98 Short-term debt 2 us-gaap_ShortTermBorrowings us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 0 0 false false 2 false true 125000000 125 false false No definition available. No authoritative reference available. false 99 Current maturities of long-term debt 2 us-gaap_LongTermDebtCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 16000000 16 false false 2 false true 50000000 50 false false No definition available. No authoritative reference available. false 100 Accounts payable and accrued liabilities 2 us-gaap_AccountsPayableAndAccruedLiabilities us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 150000000 150 false false 2 false true 187000000 187 false false No definition available. No authoritative reference available. false 101 Accounts payable due to associated companies 2 us-gaap_AccountsPayableRelatedParties us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 64000000 64 false false 2 false true 70000000 70 false false No definition available. No authoritative reference available. false 102 Capital lease obligations due within one year 2 us-gaap_CapitalLeaseObligationsCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 7000000 7 false false 2 false true 6000000 6 false false No definition available. No authoritative reference available. false 103 Taxes accrued 2 us-gaap_TaxesPayable us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 42000000 42 false false 2 false true 44000000 44 false false No definition available. No authoritative reference available. false 104 Interest accrued 2 us-gaap_InterestPayable us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 18000000 18 false false 2 false true 19000000 19 false false No definition available. No authoritative reference available. false 105 Liabilities and accrued interest related to uncertain tax positions 2 us-gaap_LiabilityForUncertainTaxPositionsCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 0 0 false false 2 false true 38000000 38 false false No definition available. No authoritative reference available. false 107 Other 2 us-gaap_OtherLiabilitiesCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 133000000 133 false false 2 false true 94000000 94 false false No definition available. No authoritative reference available. false 108 Total Current Liabilities 2 us-gaap_LiabilitiesCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 430000000 430 false false 2 false true 633000000 633 false false No definition available. No authoritative reference available. true 109 DEFERRED CREDITS 2 pom false na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 110 Regulatory liabilities 2 us-gaap_RegulatoryLiabilityNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 205000000 205 false false 2 false true 239000000 239 false false No definition available. No authoritative reference available. false 111 Deferred income taxes, net 2 us-gaap_DeferredTaxLiabilitiesNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 794000000 794 false false 2 false true 788000000 788 false false No definition available. No authoritative reference available. false 112 Investment tax credits 2 us-gaap_AccumulatedDeferredInvestmentTaxCredit us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 9000000 9 false false 2 false true 10000000 10 false false No definition available. No authoritative reference available. false 115 Other postretirement benefit obligation 2 us-gaap_OtherPostretirementDefinedBenefitPlanNoncurrentLiabilities us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 49000000 49 false false 2 false true 49000000 49 false false No definition available. No authoritative reference available. false 116 Income taxes payable 2 pom_IncomeTaxesPayableNoncurrent pom false credit instant monetary No definition available. false false false false false false false false false 1 false true 133000000 133 false false 2 false true 137000000 137 false false No definition available. No authoritative reference available. false 119 Other 2 us-gaap_OtherLiabilitiesNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 78000000 78 false false 2 false true 65000000 65 false false No definition available. No authoritative reference available. false 120 Total Deferred Credits 2 pom_TotalDeferredCreditsAndOtherLiabilities pom false credit instant monetary No definition available. false false false false false false false false false 1 false true 1268000000 1268 false false 2 false true 1288000000 1288 false false No definition available. No authoritative reference available. true 121 LONG-TERM LIABILITIES 2 pom false na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 122 Long-term debt 2 us-gaap_LongTermDebtNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 1538000000 1538 false false 2 false true 1445000000 1445 false false No definition available. No authoritative reference available. false 125 Capital lease obligations 2 us-gaap_CapitalLeaseObligationsNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 96000000 96 false false 2 false true 99000000 99 false false No definition available. No authoritative reference available. false 126 Total Long-Term Liabilities 2 us-gaap_LongTermDebtAndCapitalLeaseObligations us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 1634000000 1634 false false 2 false true 1544000000 1544 false false No definition available. No authoritative reference available. true 128 COMMITMENTS AND CONTINGENCIES 2 us-gaap_CommitmentsAndContingencies us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 0 0 false false 2 false true 0 0 false false No definition available. No authoritative reference available. false 130 EQUITY 2 pom false na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 131 Common stock 2 us-gaap_CommonStockValue us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 0 0 false false 2 false true 0 0 false false No definition available. No authoritative reference available. false 132 Premium on stock and other capital contributions 2 us-gaap_AdditionalPaidInCapitalCommonStock us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 661000000 661 false false 2 false true 611000000 611 false false No definition available. No authoritative reference available. false 134 Retained earnings 2 us-gaap_RetainedEarningsAccumulatedDeficit us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 660000000 660 false false 2 false true 624000000 624 false false No definition available. No authoritative reference available. false 135 Total Equity 2 us-gaap_StockholdersEquity us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 1321000000 1321 false false 2 false true 1235000000 1235 false false No definition available. No authoritative reference available. true 138 TOTAL LIABILITIES AND EQUITY 2 us-gaap_LiabilitiesAndStockholdersEquity us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 4653000000 4653 false false 2 false true 4700000000 4700 false false No definition available. No authoritative reference available. true 139 DELMARVA POWER & LIGHT CO /DE/ 0 na true na na na No definition available. false true false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. No authoritative reference available. false 140 CURRENT ASSETS 2 us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 141 Cash and cash equivalents 2 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 115000000 115 false false 2 false true 138000000 138 false false No definition available. No authoritative reference available. false 143 Accounts receivable, less allowance for uncollectible accounts 2 us-gaap_AccountsReceivableNetCurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 170000000 170 false false 2 false true 202000000 202 false false No definition available. No authoritative reference available. false 144 Inventories 2 us-gaap_InventoryNet us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 41000000 41 false false 2 false true 52000000 52 false false No definition available. No authoritative reference available. false 146 Prepayments of income taxes 2 us-gaap_PrepaidTaxes us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 54000000 54 false false 2 false true 34000000 34 false false No definition available. No authoritative reference available. false 147 Prepaid expenses and other 2 us-gaap_OtherAssetsCurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 23000000 23 false false 2 false true 28000000 28 false false No definition available. No authoritative reference available. false 148 Total Current Assets 2 us-gaap_AssetsCurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 403000000 403 false false 2 false true 454000000 454 false false No definition available. No authoritative reference available. true 149 INVESTMENTS AND OTHER ASSETS 2 pom false na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 150 Goodwill 2 us-gaap_Goodwill us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 8000000 8 false false 2 false true 8000000 8 false false No definition available. No authoritative reference available. false 151 Regulatory assets 2 us-gaap_RegulatoryAssetsNoncurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 214000000 214 false false 2 false true 244000000 244 false false No definition available. No authoritative reference available. false 152 Prepaid pension expense 2 us-gaap_PrepaidPensionCosts us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 187000000 187 false false 2 false true 184000000 184 false false No definition available. No authoritative reference available. false 159 Other 2 us-gaap_OtherAssetsNoncurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 47000000 47 false false 2 false true 33000000 33 false false No definition available. No authoritative reference available. false 160 Total Investments and Other Assets 2 pom_TotalInvestmentsAndOtherAssets pom false debit instant monetary No definition available. false false false false false false false false false 1 false true 456000000 456 false false 2 false true 469000000 469 false false No definition available. No authoritative reference available. true 161 PROPERTY, PLANT AND EQUIPMENT 2 us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 162 Property, plant and equipment 2 us-gaap_PropertyPlantAndEquipmentGross us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 2724000000 2724 false false 2 false true 2656000000 2656 false false No definition available. No authoritative reference available. false 163 Accumulated depreciation 2 us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true -845000000 -845 false false 2 false true -827000000 -827 false false No definition available. No authoritative reference available. false 164 Net Property, Plant and Equipment 2 us-gaap_PropertyPlantAndEquipmentNet us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 1879000000 1879 false false 2 false true 1829000000 1829 false false No definition available. No authoritative reference available. true 165 TOTAL ASSETS 2 us-gaap_Assets us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 2738000000 2738 false false 2 false true 2752000000 2752 false false No definition available. No authoritative reference available. true 166 CURRENT LIABILITIES 2 us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 167 Short-term debt 2 us-gaap_ShortTermBorrowings us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 255000000 255 false false 2 false true 246000000 246 false false No definition available. No authoritative reference available. false 169 Accounts payable and accrued liabilities 2 us-gaap_AccountsPayableAndAccruedLiabilities us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 64000000 64 false false 2 false true 108000000 108 false false No definition available. No authoritative reference available. false 170 Accounts payable due to associated companies 2 us-gaap_AccountsPayableRelatedParties us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 22000000 22 false false 2 false true 34000000 34 false false No definition available. No authoritative reference available. false 172 Taxes accrued 2 us-gaap_TaxesPayable us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 4000000 4 false false 2 false true 7000000 7 false false No definition available. No authoritative reference available. false 173 Interest accrued 2 us-gaap_InterestPayable us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 6000000 6 false false 2 false true 6000000 6 false false No definition available. No authoritative reference available. false 174 Liabilities and accrued interest related to uncertain tax positions 2 us-gaap_LiabilityForUncertainTaxPositionsCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 0 0 false false 2 false true 23000000 23 false false No definition available. No authoritative reference available. false 175 Derivative liabilities 2 us-gaap_DerivativeLiabilitiesCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 11000000 11 false false 2 false true 13000000 13 false false No definition available. No authoritative reference available. false 176 Other 2 us-gaap_OtherLiabilitiesCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 77000000 77 false false 2 false true 56000000 56 false false No definition available. No authoritative reference available. false 177 Total Current Liabilities 2 us-gaap_LiabilitiesCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 439000000 439 false false 2 false true 493000000 493 false false No definition available. No authoritative reference available. true 178 DEFERRED CREDITS 2 pom false na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 179 Regulatory liabilities 2 us-gaap_RegulatoryLiabilityNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 290000000 290 false false 2 false true 277000000 277 false false No definition available. No authoritative reference available. false 180 Deferred income taxes, net 2 us-gaap_DeferredTaxLiabilitiesNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 467000000 467 false false 2 false true 446000000 446 false false No definition available. No authoritative reference available. false 181 Investment tax credits 2 us-gaap_AccumulatedDeferredInvestmentTaxCredit us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 8000000 8 false false 2 false true 8000000 8 false false No definition available. No authoritative reference available. false 182 Above-market purchased energy contracts and other electric restructuring liabilities 2 us-gaap_RestructuringReserveNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 18000000 18 false false 2 false true 19000000 19 false false No definition available. No authoritative reference available. false 187 Derivative liabilities 2 us-gaap_DerivativeLiabilitiesNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 19000000 19 false false 2 false true 14000000 14 false false No definition available. No authoritative reference available. false 188 Other 2 us-gaap_OtherLiabilitiesNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 61000000 61 false false 2 false true 57000000 57 false false No definition available. No authoritative reference available. false 189 Total Deferred Credits 2 pom_TotalDeferredCreditsAndOtherLiabilities pom false credit instant monetary No definition available. false false false false false false false false false 1 false true 863000000 863 false false 2 false true 821000000 821 false false No definition available. No authoritative reference available. true 190 LONG-TERM LIABILITIES 2 pom false na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 191 Long-term debt 2 us-gaap_LongTermDebtNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 686000000 686 false false 2 false true 686000000 686 false false No definition available. No authoritative reference available. false 197 COMMITMENTS AND CONTINGENCIES 2 us-gaap_CommitmentsAndContingencies us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 0 0 false false 2 false true 0 0 false false No definition available. No authoritative reference available. false 199 EQUITY 2 pom false na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 200 Common stock 2 us-gaap_CommonStockValue us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 0 0 false false 2 false true 0 0 false false No definition available. No authoritative reference available. false 201 Premium on stock and other capital contributions 2 us-gaap_AdditionalPaidInCapitalCommonStock us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 304000000 304 false false 2 false true 304000000 304 false false No definition available. No authoritative reference available. false 203 Retained earnings 2 us-gaap_RetainedEarningsAccumulatedDeficit us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 446000000 446 false false 2 false true 448000000 448 false false No definition available. No authoritative reference available. false 204 Total Equity 2 us-gaap_StockholdersEquity us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 750000000 750 false false 2 false true 752000000 752 false false No definition available. No authoritative reference available. true 207 TOTAL LIABILITIES AND EQUITY 2 us-gaap_LiabilitiesAndStockholdersEquity us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 2738000000 2738 false false 2 false true 2752000000 2752 false false No definition available. No authoritative reference available. true 208 ATLANTIC CITY ELECTRIC CO 0 na true na na na No definition available. false true false false false false false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. No authoritative reference available. false 209 CURRENT ASSETS 2 us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 210 Cash and cash equivalents 2 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 5000000 5 false false 2 false true 65000000 65 false false No definition available. No authoritative reference available. false 211 Restricted cash equivalents 2 us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 9000000 9 false false 2 false true 10000000 10 false false No definition available. No authoritative reference available. false 212 Accounts receivable, less allowance for uncollectible accounts 2 us-gaap_AccountsReceivableNetCurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 163000000 163 false false 2 false true 195000000 195 false false No definition available. No authoritative reference available. false 213 Inventories 2 us-gaap_InventoryNet us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 16000000 16 false false 2 false true 15000000 15 false false No definition available. No authoritative reference available. false 215 Prepayments of income taxes 2 us-gaap_PrepaidTaxes us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 40000000 40 false false 2 false true 47000000 47 false false No definition available. No authoritative reference available. false 216 Prepaid expenses and other 2 us-gaap_OtherAssetsCurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 74000000 74 false false 2 false true 16000000 16 false false No definition available. No authoritative reference available. false 217 Total Current Assets 2 us-gaap_AssetsCurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 307000000 307 false false 2 false true 348000000 348 false false No definition available. No authoritative reference available. true 218 INVESTMENTS AND OTHER ASSETS 2 pom false na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 220 Regulatory assets 2 us-gaap_RegulatoryAssetsNoncurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 742000000 742 false false 2 false true 768000000 768 false false No definition available. No authoritative reference available. false 221 Prepaid pension expense 2 us-gaap_PrepaidPensionCosts us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 62000000 62 false false 2 false true 6000000 6 false false No definition available. No authoritative reference available. false 224 Income taxes receivable 2 pom_IncomeTaxesReceivableNoncurrent pom false debit instant monetary No definition available. false false false false false false false false false 1 false true 75000000 75 false false 2 false true 12000000 12 false false No definition available. No authoritative reference available. false 225 Restricted cash equivalents 2 us-gaap_RestrictedCashAndCashEquivalentsNoncurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 5000000 5 false false 2 false true 5000000 5 false false No definition available. No authoritative reference available. false 226 Assets and accrued interest related to uncertain tax positions 2 pom_AssetsAndAccruedInterestRelatedToUncertainTaxPositionsNoncurrent pom false debit instant monetary No definition available. false false false false false false false false false 1 false true 77000000 77 false false 2 false true 113000000 113 false false No definition available. No authoritative reference available. false 228 Other 2 us-gaap_OtherAssetsNoncurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 12000000 12 false false 2 false true 12000000 12 false false No definition available. No authoritative reference available. false 229 Total Investments and Other Assets 2 pom_TotalInvestmentsAndOtherAssets pom false debit instant monetary No definition available. false false false false false false false false false 1 false true 973000000 973 false false 2 false true 916000000 916 false false No definition available. No authoritative reference available. true 230 PROPERTY, PLANT AND EQUIPMENT 2 us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 231 Property, plant and equipment 2 us-gaap_PropertyPlantAndEquipmentGross us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 2267000000 2267 false false 2 false true 2216000000 2216 false false No definition available. No authoritative reference available. false 232 Accumulated depreciation 2 us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true -684000000 -684 false false 2 false true -666000000 -666 false false No definition available. No authoritative reference available. false 233 Net Property, Plant and Equipment 2 us-gaap_PropertyPlantAndEquipmentNet us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 1583000000 1583 false false 2 false true 1550000000 1550 false false No definition available. No authoritative reference available. true 234 TOTAL ASSETS 2 us-gaap_Assets us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 2863000000 2863 false false 2 false true 2814000000 2814 false false No definition available. No authoritative reference available. true 235 CURRENT LIABILITIES 2 us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 236 Short-term debt 2 us-gaap_ShortTermBorrowings us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 139000000 139 false false 2 false true 23000000 23 false false No definition available. No authoritative reference available. false 237 Current maturities of long-term debt 2 us-gaap_LongTermDebtCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 33000000 33 false false 2 false true 32000000 32 false false No definition available. No authoritative reference available. false 238 Accounts payable and accrued liabilities 2 us-gaap_AccountsPayableAndAccruedLiabilities us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 120000000 120 false false 2 false true 122000000 122 false false No definition available. No authoritative reference available. false 239 Accounts payable due to associated companies 2 us-gaap_AccountsPayableRelatedParties us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 29000000 29 false false 2 false true 28000000 28 false false No definition available. No authoritative reference available. false 241 Taxes accrued 2 us-gaap_TaxesPayable us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 15000000 15 false false 2 false true 7000000 7 false false No definition available. No authoritative reference available. false 242 Interest accrued 2 us-gaap_InterestPayable us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 14000000 14 false false 2 false true 14000000 14 false false No definition available. No authoritative reference available. false 243 Liabilities and accrued interest related to uncertain tax positions 2 us-gaap_LiabilityForUncertainTaxPositionsCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 0 0 false false 2 false true 6000000 6 false false No definition available. No authoritative reference available. false 245 Other 2 us-gaap_OtherLiabilitiesCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 38000000 38 false false 2 false true 35000000 35 false false No definition available. No authoritative reference available. false 246 Total Current Liabilities 2 us-gaap_LiabilitiesCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 388000000 388 false false 2 false true 267000000 267 false false No definition available. No authoritative reference available. true 247 DEFERRED CREDITS 2 pom false na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 248 Regulatory liabilities 2 us-gaap_RegulatoryLiabilityNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 259000000 259 false false 2 false true 377000000 377 false false No definition available. No authoritative reference available. false 249 Deferred income taxes, net 2 us-gaap_DeferredTaxLiabilitiesNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 570000000 570 false false 2 false true 549000000 549 false false No definition available. No authoritative reference available. false 250 Investment tax credits 2 us-gaap_AccumulatedDeferredInvestmentTaxCredit us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 10000000 10 false false 2 false true 10000000 10 false false No definition available. No authoritative reference available. false 253 Other postretirement benefit obligation 2 us-gaap_OtherPostretirementDefinedBenefitPlanNoncurrentLiabilities us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 43000000 43 false false 2 false true 41000000 41 false false No definition available. No authoritative reference available. false 255 Liabilities and accrued interest related to uncertain tax positions 2 us-gaap_LiabilityForUncertainTaxPositionsNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 12000000 12 false false 2 false true 3000000 3 false false No definition available. No authoritative reference available. false 257 Other 2 us-gaap_OtherLiabilitiesNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 17000000 17 false false 2 false true 14000000 14 false false No definition available. No authoritative reference available. false 258 Total Deferred Credits 2 pom_TotalDeferredCreditsAndOtherLiabilities pom false credit instant monetary No definition available. false false false false false false false false false 1 false true 911000000 911 false false 2 false true 994000000 994 false false No definition available. No authoritative reference available. true 259 LONG-TERM LIABILITIES 2 pom false na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 260 Long-term debt 2 us-gaap_LongTermDebtNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 610000000 610 false false 2 false true 610000000 610 false false No definition available. No authoritative reference available. false 261 Transition bonds issued by ACE Funding 2 us-gaap_LongTermTransitionBond us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 385000000 385 false false 2 false true 401000000 401 false false No definition available. No authoritative reference available. false 265 Total Long-Term Liabilities 2 pom_TotalOtherLongTermLiabilities pom false credit instant monetary No definition available. false false false false false false false false false 1 false true 995000000 995 false false 2 false true 1011000000 1011 false false No definition available. No authoritative reference available. true 266 COMMITMENTS AND CONTINGENCIES 2 us-gaap_CommitmentsAndContingencies us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 0 0 false false 2 false true 0 0 false false No definition available. No authoritative reference available. false 267 REDEEMABLE SERIAL PREFERRED STOCK 2 us-gaap_PreferredStockValueOutstanding us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 6000000 6 false false 2 false true 6000000 6 false false No definition available. No authoritative reference available. false 268 EQUITY 2 pom false na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 269 Common stock 2 us-gaap_CommonStockValue us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 26000000 26 false false 2 false true 26000000 26 false false No definition available. No authoritative reference available. false 270 Premium on stock and other capital contributions 2 us-gaap_AdditionalPaidInCapitalCommonStock us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 385000000 385 false false 2 false true 344000000 344 false false No definition available. No authoritative reference available. false 272 Retained earnings 2 us-gaap_RetainedEarningsAccumulatedDeficit us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 152000000 152 false false 2 false true 166000000 166 false false No definition available. No authoritative reference available. false 273 Total Equity 2 us-gaap_StockholdersEquity us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 563000000 563 false false 2 false true 536000000 536 false false No definition available. No authoritative reference available. true 276 TOTAL LIABILITIES AND EQUITY 2 us-gaap_LiabilitiesAndStockholdersEquity us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 true true 2863000000 2863 false false 2 true true 2814000000 2814 false false No definition available. No authoritative reference available. true false 2 213 false Millions UnKnown UnKnown false true