Face (par) amount of debt instrument at time of issuance.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The amount of any significant sales of financing receivables during the reporting period.

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The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

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Net increase or decrease in the carrying amount of the credit facility for the period for reasons other than accrued, but unpaid interest, additional borrowings, repayments, and forgiveness.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount of long-term debt, after unamortized discount or premium, scheduled to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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The cash outflow to settle a bank borrowing during the year.

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The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer.

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The cash outflow to repay long-term debt that is wholly or partially secured by collateral. Excludes repayments of tax exempt secured debt.

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If the value of securities and cash collateralizing a secured demand note contributed for purposes of capital under regulatory reporting requirements after application of the deductions specified therein is less than the unpaid principal amount of the secured demand note, such deficiency is deducted.

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Carrying amount at the balance sheet date of borrowings from a bank, not elsewhere enumerated in the taxonomy, with a maturity within one year (or within one operating cycle if longer) from the date of borrowing.

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The portion of the carrying amount of short-term borrowings outstanding as of the balance sheet date, which accrues interest at a rate subject to change from time to time.

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No definition available.

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Debt and Credit Agreements - Narrative (Details) - USD ($)						1 Months Ended	3 Months Ended
	Apr. 20, 2016	Apr. 15, 2016	Apr. 05, 2016	Apr. 01, 2016	Feb. 29, 2016	Feb. 29, 2016	Mar. 31, 2016	Mar. 31, 2015	Apr. 07, 2016	Jan. 13, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Repayments of Long-term Debt							$ 116,000,000	$ 580,000,000
Debt Instrument, Face Amount								750,000,000
Subsequent Event [Member] \| Senior Loans [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount									$ 1,800,000,000
Subsequent Event [Member] \| SeniorNotes2021 [Member] \| Senior Loans [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount									300,000,000
Subsequent Event [Member] \| SeniorNotes2026 [Member] \| Senior Loans [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount									750,000,000
Subsequent Event [Member] \| SeniorNotes2046 [Member] \| Senior Loans [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount									$ 750,000,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity							100,000,000
Revolving Credit Facility [Member] \| Subsequent Event [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity				$ 200,000,000
Exelon Generation Co L L C [Member]
Debt Instrument [Line Items]
Repayments of Long-term Debt							$ 94,000,000	18,000,000
Interest Rate											2.74%
Exelon Generation Co L L C [Member] \| Unsecured Debt [Member]
Debt Instrument [Line Items]
Interest Rate							4.11%
Debt Instrument, Face Amount							$ 150,000,000
Exelon Generation Co L L C [Member] \| Non Recourse Debt [Member]
Debt Instrument [Line Items]
Repayments of Long-term Debt			$ 1,000,000
Exelon Generation Co L L C [Member] \| ExgenRenewablesI425June62021[Member] \| Non Recourse Debt [Member]
Debt Instrument [Line Items]
Repayments of Long-term Debt		$ 10,000,000
Interest Rate		5.25%
Exelon Generation Co L L C [Member] \| Subsequent Event [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount							25,000,000
Exelon Generation Co L L C [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity							150,000,000
Atlantic City Electric Company [Member]
Debt Instrument [Line Items]
Repayments of Long-term Debt	$ 3,000,000.0000						$ 11,000,000	$ 10,000,000
Atlantic City Electric Company [Member] \| Transition Bonds555October2023 [Member]
Debt Instrument [Line Items]
Repayments of Long-term Debt	$ 8,000,000.0000
Interest Rate							5.55%
Repayments of Secured Debt							$ 8,000,000.0000
Baltimore Gas and Electric Company [Member]
Debt Instrument [Line Items]
Repayments of Bank Debt				$ 1,000,000
Interest Rate				5.72%
Baltimore Gas and Electric Company [Member] \| Convertible Debt Securities [Member]
Debt Instrument [Line Items]
Repayments of Bank Debt				$ 38,000,000
Interest Rate				5.82%
Pepco Holdings, LLC [Member] \| Subsequent Event [Member]
Debt Instrument [Line Items]
Short-term Bank Loans and Notes Payable										$ 500,000,000
Short-term Debt, Percentage Bearing Variable Interest Rate										1.00%
Repayments of Bank Debt							300,000,000
Pepco Energy Services [Member]
Debt Instrument [Line Items]
Long-term Debt, Current Maturities							3,000,000
Financing Receivable, Significant Sales						$ 41,000,000
Delmarva Power and Light Company [Member] \| Variable Rate Demand Obligation [Member]
Debt Instrument [Line Items]
Long-term Debt, Current Maturities							105,000,000
CEU Holdings, LLC [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Increase (Decrease), Other, Net					$ 45,000,000
Secured Demand Note Deficiency					$ 23,000,000	$ 23,000,000	16,000,000
Outstanding borrowings/facility draws											$ 85,000,000
Line of Credit Facility, Maximum Borrowing Capacity							500,000,000
Long-term Debt							$ 61,000,000				$ 68,000,000