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us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ 5 Change in plan assets 3 us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward us-gaap true na duration No definition available. false false false false false true false false false false false false 1 false false false false 0 0 false false false 2 false false false false 0 0 true false false 3 false false false false 0 0 true false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 true false false 8 false false false false 0 0 true false false 9 false false false false 0 0 true false false 10 false false false false 0 0 true false false 11 false false false false 0 0 true false false 12 false false false false 0 0 true false false 13 false false false false 0 0 true false false xbrli:stringItemType string A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. false 6 Fair value of plan assets at beginning of period 4 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets us-gaap true debit instant No definition available. false false false false false false false false true false false periodstartlabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 true false false 3 false false false false 0 0 true false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 true false false 8 true true false false 867600000 867600000 true false false 9 true true false false 1258500000 1258500000 true false false 10 false false false false 0 0 true false false 11 false false false false 0 0 true false false 12 false false false false 0 0 true false false 13 false false false false 0 0 true false false xbrli:monetaryItemType monetary Assets, usually stocks, bonds, and other investments, that have been segregated and restricted (usually in a trust) to provide benefits, at their fair value as of the measurement date. Plan assets include amounts contributed by the employer (and by employees for a contributory plan) and amounts earned from investing the contributions, less benefits paid. If a plan has liabilities other than for benefits, those nonbenefit obligations may be considered as reductions of plan assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph b Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph d(iv)(b)(i) Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 87 -Paragraph 49 false 7 Actual return on plan assets 4 us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets us-gaap true debit duration No definition available. false false false false false false false false false false false terselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 true false false 3 false false false false 0 0 true false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 true false false 8 false true false false 217600000 217600000 true false false 9 false true false false -364900000 -364900000 true false false 10 false false false false 0 0 true false false 11 false false false false 0 0 true false false 12 false false false false 0 0 true false false 13 false false false false 0 0 true false false xbrli:monetaryItemType monetary The difference between fair value of plan assets at the end of the period and the fair value at the beginning of the period, adjusted for contributions and payments of benefits during the period, and after adjusting for taxes and other expenses, as applicable. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph d(iv)(b)(i) Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 106 -Paragraph 518 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 Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph b false 8 Employer contribution 4 us-gaap_DefinedBenefitPlanContributionsByEmployer us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 true false false 3 false false false false 0 0 true false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 true false false 8 false true false false 341500000 341500000 [1] true false false 9 false true false false 86200000 86200000 [1] true false false 10 false false false false 0 0 true false false 11 false true false false 24400000 24400000 [1] true false false 12 false true false false 27500000 27500000 [1] true false false 13 false false false false 0 0 true false false xbrli:monetaryItemType monetary The amount of contributions made by the employer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph b false 9 Plan participants' contributions 4 ceg_DefinedBenefitPlanContributionsByPlanParticipantsAssets ceg false debit duration The increase to plan assets resulting from the amount of contributions made by plan participants. false false false false false false false false false false false terselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 true false false 3 false false false false 0 0 true false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 true false false 8 false false false false 0 0 true false false 9 false false false false 0 0 true false false 10 false false false false 0 0 true false false 11 false true false false 10200000 10200000 true false false 12 false true false false 10800000 10800000 true false false 13 false false false false 0 0 true false false xbrli:monetaryItemType monetary The increase to plan assets resulting from the amount of contributions made by plan participants. No authoritative reference available. false 10 Separation of CENG Plan 4 us-gaap_DefinedBenefitPlanDivestituresPlanAssets us-gaap true credit duration No definition available. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 true false false 3 false false false false 0 0 true false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 true false false 8 false true false false -234400000 -234400000 true false false 9 false false false false 0 0 true false false 10 false false false false 0 0 true false false 11 false false false false 0 0 true false false 12 false false false false 0 0 true false false 13 false false false false 0 0 true false false xbrli:monetaryItemType monetary The amount of decrease in the plan assets attributed to the sale, liquidation, spin-off or other divestiture of a corporate division or subsidiary. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph b Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph d(iv)(b)(i) false 11 Settlements 4 us-gaap_DefinedBenefitPlanSettlementsPlanAssets us-gaap true credit duration No definition available. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 true false false 3 false false false false 0 0 true false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 true false false 8 false true false false -19000000 -19000000 true false false 9 false false false false 0 0 true false false 10 false false false false 0 0 true false false 11 false false false false 0 0 true false false 12 false false false false 0 0 true false false 13 false false false false 0 0 true false false xbrli:monetaryItemType monetary The amount that relates to an irrevocable action that relieves the employer (or the plan) of primary responsibility for a benefit obligation and eliminates significant risks related to the obligation and the assets used to effect the settlement. Examples of transactions that constitute a settlement include (a) making lump-sum cash payments to plan participants in exchange for their rights to receive specified benefits and (b) purchasing nonparticipating annuity contracts. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph d(iv)(b)(i) Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 88 -Paragraph 3 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 106 -Paragraph 518 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 87 -Paragraph 264 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph b false 12 Benefits paid 4 ceg_DefinedBenefitPlanBenefitsPaidAssets ceg false credit instant The decrease to plan assets resulting from the amount of benefits paid. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 true false false 3 false false false false 0 0 true false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 true false false 8 false true false false -115200000 -115200000 [2] true false false 9 false true false false -112200000 -112200000 [2] true false false 10 false false false false 0 0 true false false 11 false true false false -34600000 -34600000 [3] true false false 12 false true false false -38300000 -38300000 [3] true false false 13 false false false false 0 0 true false false xbrli:monetaryItemType monetary The decrease to plan assets resulting from the amount of benefits paid. No authoritative reference available. false 13 Fair value of plan assets at end of period 4 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets us-gaap true debit instant No definition available. false false false false false false false false false true false periodendlabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 true false false 3 false false false false 0 0 true false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 true false false 8 false true false false 1058100000 1058100000 true false false 9 false true false false 867600000 867600000 true false false 10 false true false false 1258500000 1258500000 true false false 11 false false false false 0 0 true false false 12 false false false false 0 0 true false false 13 false false false false 0 0 true false false xbrli:monetaryItemType monetary Assets, usually stocks, bonds, and other investments, that have been segregated and restricted (usually in a trust) to provide benefits, at their fair value as of the measurement date. Plan assets include amounts contributed by the employer (and by employees for a contributory plan) and amounts earned from investing the contributions, less benefits paid. If a plan has liabilities other than for benefits, those nonbenefit obligations may be considered as reductions of plan assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph b Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph d(iv)(b)(i) Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 87 -Paragraph 49 false 14 Components of net periodic pension and postretirement benefit cost 3 us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract us-gaap true na duration No definition available. false false false false false true false false false false false false 1 false false false false 0 0 false false false 2 false false false false 0 0 true false false 3 false false false false 0 0 true false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 true false false 8 false false false false 0 0 true false false 9 false false false false 0 0 true false false 10 false false false false 0 0 true false false 11 false false false false 0 0 true false false 12 false false false false 0 0 true false false 13 false false false false 0 0 true false false xbrli:stringItemType string No definition available. false 15 Service cost 4 us-gaap_DefinedBenefitPlanServiceCost us-gaap true debit duration No definition available. false false false false false false false false false false false terselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 true false false 3 false false false false 0 0 true false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 true false false 8 false true false false 50800000 50800000 true false false 9 false true false false 55400000 55400000 true false false 10 false true false false 49400000 49400000 true false false 11 false true false false 6300000 6300000 true false false 12 false true false false 6100000 6100000 true false false 13 false true false false 6500000 6500000 true false false xbrli:monetaryItemType monetary The actuarial present value of benefits attributed by the pension benefit formula to services rendered by employees during the period. The portion of the expected postretirement benefit obligation attributed to employee service during the period. The service cost component is a portion of the benefit obligation and is unaffected by the funded status of the plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 106 -Paragraph 518 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 87 -Paragraph 264 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph a, h false 16 Interest cost 4 us-gaap_DefinedBenefitPlanInterestCost us-gaap true debit duration No definition available. false false false false false false false false false false false terselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 true false false 3 false false false false 0 0 true false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 true false false 8 false true false false 101100000 101100000 true false false 9 false true false false 100200000 100200000 true false false 10 false true false false 94700000 94700000 true false false 11 false true false false 22600000 22600000 true false false 12 false true false false 24000000 24000000 true false false 13 false true false false 24400000 24400000 true false false xbrli:monetaryItemType monetary The increase in a defined benefit pension plan's projected benefit obligation or a defined benefit postretirement plan's accumulated postretirement benefit obligation due to the passage of time. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 106 -Paragraph 518 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 87 -Paragraph 264 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph a, h false 17 Expected return on plan assets 4 us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets us-gaap true credit duration No definition available. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 true false false 3 false false false false 0 0 true false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 true false false 8 false true false false -118900000 -118900000 true false false 9 false true false false -111300000 -111300000 true false false 10 false true false false -102600000 -102600000 true false false 11 false false false false 0 0 true false false 12 false false false false 0 0 true false false 13 false false false false 0 0 true false false xbrli:monetaryItemType monetary An amount calculated as a basis for determining the extent of delayed recognition of the effects of changes in the fair value of assets. The expected return on plan assets is determined based on the expected long-term rate of return on plan assets and the market-related value of plan assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 106 -Paragraph 518 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 87 -Paragraph 264 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph h false 18 Amortization of transition obligation 4 us-gaap_DefinedBenefitPlanAmortizationOfTransitionObligationsAssets us-gaap true debit duration No definition available. false false false false false false false false false false false terselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 true false false 3 false false false false 0 0 true false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 true false false 8 false false false false 0 0 true false false 9 false false false false 0 0 true false false 10 false false false false 0 0 true false false 11 false true false false 2100000 2100000 true false false 12 false true false false 2100000 2100000 true false false 13 false true false false 2100000 2100000 true false false xbrli:monetaryItemType monetary The amount of the transition obligation or asset recognized in net periodic benefit cost. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph h false 19 Amortization of unrecognized prior service cost 4 us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit us-gaap true debit duration No definition available. false false false false false false false false false false false terselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 true false false 3 false false false false 0 0 true false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 true false false 8 false true false false 10900000 10900000 true false false 9 false true false false 10900000 10900000 true false false 10 false true false false 5200000 5200000 true false false 11 false true false false -3400000 -3400000 true false false 12 false true false false -3500000 -3500000 true false false 13 false true false false -3500000 -3500000 true false false xbrli:monetaryItemType monetary The amount of the prior service cost or credit recognized in net periodic benefit cost relating to benefit changes attributable to plan participants' prior service pursuant to a plan amendment or a plan initiation. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph h false 20 Recognized net actuarial loss 4 us-gaap_DefinedBenefitPlanActuarialNetGainsLosses us-gaap true debit duration No definition available. false false false false false false false false false false false terselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 true false false 3 false false false false 0 0 true false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 true false false 8 false true false false 38300000 38300000 true false false 9 false true false false 24700000 24700000 true false false 10 false true false false 32700000 32700000 true false false 11 false true false false 2200000 2200000 true false false 12 false true false false 2000000 2000000 true false false 13 false true false false 4100000 4100000 true false false xbrli:monetaryItemType monetary The net increase or decrease of changes in the value of either the benefit obligation or the plan assets resulting from experience different from that assumed or from a change in an actuarial assumption, or the consequence of a decision to temporarily deviate from the substantive plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 106 -Paragraph 518 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 87 -Paragraph 264 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph a false 21 Amount capitalized as construction cost 4 ceg_DefinedBenefitPlanNetPeriodicBenefitCostCapitalized ceg false credit duration The portion of the total amount of net periodic benefit cost for defined benefit plans that was capitalized during the... false false false false false false false false false false false terselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 true false false 3 false false false false 0 0 true false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 true false false 8 false true false false -10200000 -10200000 true false false 9 false true false false -10200000 -10200000 true false false 10 false true false false -11700000 -11700000 true false false 11 false true false false -6300000 -6300000 true false false 12 false true false false -7600000 -7600000 true false false 13 false true false false -7700000 -7700000 true false false xbrli:monetaryItemType monetary The portion of the total amount of net periodic benefit cost for defined benefit plans that was capitalized during the period. No authoritative reference available. false 22 Net periodic pension and postretirement benefit cost (1) 4 us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost us-gaap true debit duration No definition available. false false false false false false false false false false false terselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 true false false 3 false false false false 0 0 true false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 true false false 8 false true false false 72000000 72000000 [4] true false false 9 false true false false 69700000 69700000 [4] true false false 10 false true false false 67700000 67700000 [4] true false false 11 false true false false 23500000 23500000 [5] true false false 12 false true false false 23100000 23100000 [5] true false false 13 false true false false 25900000 25900000 [5] true false false xbrli:monetaryItemType monetary The total amount of net periodic benefit cost for defined benefit plans for the period. Periodic benefit costs include the following components: service cost, interest cost, expected return on plan assets, gain or loss, prior service cost or credit, transition asset or obligation, and gain or loss due to settlements or curtailments). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph h false 23 Net periodic pension and postretirement benefit cost, excluding capitalized costs 4 ceg_DefinedBenefitPlanNetPeriodicBenefitCostExcludingCapitalizedCosts ceg false debit duration The total amount of net periodic benefit cost for defined benefit plans for the period, excluding capitalized costs. Periodic... false false false false false false false false false false false terselabel false 1 false false false false 0 0 false false false 2 false true false false 27900000 27900000 true false false 3 false true false false 25500000 25500000 true false false 4 false true false false 32100000 32100000 true false false 5 false true false false 18700000 18700000 true false false 6 false true false false 20400000 20400000 true false false 7 false true false false 22700000 22700000 true false false 8 false false false false 0 0 true false false 9 false false false false 0 0 true false false 10 false false false false 0 0 true false false 11 false false false false 0 0 true false false 12 false false false false 0 0 true false false 13 false false false false 0 0 true false false xbrli:monetaryItemType monetary The total amount of net periodic benefit cost for defined benefit plans for the period, excluding capitalized costs. Periodic benefit costs include the following components: service cost, interest cost, expected return on plan assets, gain or loss, prior service cost or credit, transition asset or obligation, and gain or loss due to settlements or curtailments). No authoritative reference available. false 24 Settlement charges excluded from net periodic pension benefit costs 4 ceg_DefinedBenefitPlanSettlementsExcludedFromNetPeriodicPensionBenefitCost ceg false debit duration The amount of settlement charges excluded from net periodic pension benefit costs in the period. false false false false false false false false false false false terselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 true false false 3 false false false false 0 0 true false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 true false false 8 false true false false 9000000 9000000 true false false 9 false false false false 0 0 true false false 10 false false false false 0 0 true false false 11 false false false false 0 0 true false false 12 false false false false 0 0 true false false 13 false false false false 0 0 true false false xbrli:monetaryItemType monetary The amount of settlement charges excluded from net periodic pension benefit costs in the period. No authoritative reference available. false 25 Termination benefits excluded from net periodic defined benefit costs 4 ceg_DefinedBenefitPlanSpecialTerminationBenefitsExcludedFromNetPeriodicBenefitCost ceg false credit duration The amount of termination benefits excluded from net periodic defined benefit costs in the period. false false false false false false false false false false false terselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 true false false 3 false false false false 0 0 true false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 true false false 8 true true false false 100000 100000 true false false 9 true true false false 2200000 2200000 true false false 10 true true false false 1200000 1200000 true false false 11 false false false false 0 0 true false false 12 true true false false 800000 800000 true false false 13 true true false false 300000 300000 true false false xbrli:monetaryItemType monetary The amount of termination benefits excluded from net periodic defined benefit costs in the period. No authoritative reference available. false 26 Term to which expected asset gains and losses are ratably applied when determining net periodic pension benefit cost (in years) 4 ceg_TermOverWhichGainsLossesAreRatablyAppliedToDetermineNetPeriodicPensonBenefitCostYears ceg false na duration Term to which expected asset gains and losses are ratably applied when determining net periodic pension benefit cost, in... false false false false false false false false false false false terselabel false 1 false true false false 5 5 false false false 2 false false false false 0 0 true false false 3 false false false false 0 0 true false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 true false false 8 false false false false 0 0 true false false 9 false false false false 0 0 true false false 10 false false false false 0 0 true false false 11 false false false false 0 0 true false false 12 false false false false 0 0 true false false 13 false false false false 0 0 true false false xbrli:integerItemType integer Term to which expected asset gains and losses are ratably applied when determining net periodic pension benefit cost, in years. No authoritative reference available. false 1 Includes benefit payments for unfunded plans. 2 Pension benefits paid include annuity payments and lump-sum distributions. 3 Postretirement benefits paid are net of Medicare Part D reimbursements. 4 Net periodic pension benefit cost excludes settlement charge of $9.0 million and termination benefits of $0.1 million in 2009, termination benefits of $2.2 million in 2008, and termination benefits of $1.2 million in 2007. BGE's portion of our net periodic pension benefit costs, excluding amount capitalized, was $27.9 million in 2009, $25.5 million in 2008, and $32.1 million in 2007. The vast majority of our retirees are BGE employees. 5 Net periodic postretirement benefit cost excludes termination benefits of $0.8 million in 2008 and $0.3 million in 2007. BGE's portion of our net periodic postretirement benefit cost, excluding amounts capitalized, was $18.7 million in 2009, $20.4 million in 2008, and $22.7 million in 2007. 13 22 false NoRounding UnKnown UnKnown false true