Junior subordinate notes issued in the form of equity units

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- Definition

Loss on Reissuance, Treasury Stock

+ References

No definition available.

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- Definition

Non Recourse Debt Interest Rate Swap

+ References

No definition available.

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- Definition

The price per share of the conversion feature embedded in the debt instrument.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6928298&loc=SL6031898-161870

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Description of the interest rate as being fixed or variable, and, if variable, identification of the index or rate on which the interest rate is based and the number of points or percentage added to that index or rate to set the rate, and other pertinent information, such as frequency of rate resets.

+ References

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- Definition

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.

+ References

No definition available.

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- Definition

Gross amount of debt extinguished.

+ References

No definition available.

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- Definition

Current fair value of each cash settlement alternative for each freestanding forward contract.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 50
-Paragraph 5
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=6445032&loc=d3e90205-114008

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- Definition

Number of shares as a settlement alternative for each freestanding forward contract.

+ References

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- Definition

Including the current and noncurrent portions, carrying value as of the balance sheet date of long-term debt (with maturities initially due after one year or beyond the operating cycle if longer) identified as Junior Subordinated Notes, which have a lower priority than senior instruments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16)(a))
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- Definition

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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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
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-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

The percentage rate used to calculate dividend payments on preferred stock.

+ References

No definition available.

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Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer.

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-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Value of all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by shareholders, which is net of related treasury stock. May be all or a portion of the number of preferred shares authorized. These shares represent the ownership interest of the preferred shareholders.

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-Name Accounting Standards Codification
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- Definition

Amount of borrowings from a bank classified as other, maturing within one year or operating cycle, if longer.

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Debt and Credit Agreements - Narrative (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	1 Months Ended	3 Months Ended	6 Months Ended		9 Months Ended
	Jun. 30, 2014	Jun. 30, 2017	Jun. 30, 2017	Jun. 30, 2016	Sep. 30, 2014	Mar. 23, 2017	Jan. 09, 2017	May 26, 2016	Jan. 13, 2016	Aug. 10, 2013	Jan. 31, 2013	Aug. 01, 2011
Debt Instrument [Line Items]
Forward Contract Indexed to Issuer's Equity, Settlement Alternatives, Cash, at Fair Value		$ 1,150	$ 1,150
Extinguishment of Debt, Amount				$ 11
Junior Subordinated Debt [Member]
Debt Instrument [Line Items]
Junior Subordinated Notes		$ 1,150	$ 1,150
Equity Units Issued	23
Debt Instrument, Convertible, Conversion Price	$ 50
Interest Rate	2.50%	3.497%	3.497%
Forward Contract Indexed to Issuer's Equity, Settlement Alternatives, Shares, at Fair Value		33	33
Loss on Reissuance, Treasury Stock			$ 1,050
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity								$ 600		$ 500
Corporate, Non-Segment [Member]
Debt Instrument [Line Items]
Short-term Bank Loans and Notes Payable						$ 500
Debt Instrument, Interest Rate Terms			LIBOR plus 1%
Pepco Holdings LLC [Member]
Debt Instrument [Line Items]
Short-term Bank Loans and Notes Payable									$ 500
Debt Instrument, Interest Rate Terms			LIBOR plus 1%
Pepco Holdings LLC [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity								$ 900				$ 1,500
Exelon Generation Co L L C [Member] \| Line of Credit [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity							$ 100				$ 75
Baltimore Gas and Electric Company [Member]
Debt Instrument [Line Items]
Preferred Stock, Par or Stated Value Per Share		$ 25.19	$ 25.19
Preferred Stock, Dividend Rate, Percentage		6.20%
Preferred Stock, Redemption Amount, Future Redeemable Securities		$ 258	$ 258
ExGen Texas Power [Member] \| Exelon Generation Co L L C [Member] \| Long-term Debt [Member]
Debt Instrument [Line Items]
Long-term Debt		662	662		$ 675
Debt Instrument, Interest Rate Terms					LIBOR plus 4.75%
Line of Credit Facility, Maximum Borrowing Capacity		$ 20	$ 20
Non Recourse Debt Interest Rate Swap					$ 505
Interest Rate					2.34%