The amount remitted to variable interest entities for rate stabilization bonds.

No definition available.

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Data Type:	xbrli:monetaryItemType
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Period Type:	duration

- Definition

The number of variable interest entities (VIEs) consolidated.

+ References

No definition available.

+ Details

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- Definition

The number of variable interest entities (VIEs) not consolidated.

+ References

No definition available.

+ Details

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- Definition

This element represents the percentage of nuclear output to be purchased by third party.

+ References

No definition available.

+ Details

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- Definition

Represents the required purchases of power from a related party, that is not sold to third parties, over the specified term of a power purchase agreement, percent.

+ References

No definition available.

+ Details

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- Definition

Represents the liability recorded for severance benefits obligations as of the balance sheet date related to the corporate restructuring program.

+ References

No definition available.

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

For an unclassified balance sheet, amount of receivables due from an entity that is affiliated with the reporting entity by means of direct or indirect ownership.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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- Definition

Amount of payable due to an entity that is affiliated with the reporting entity by means of direct or indirect ownership.

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- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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- Definition

The current carrying amount of the liability for the freestanding or embedded guarantor's obligations under the guarantee or each group of similar guarantees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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- Definition

Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

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- Definition

Amount of cash payments made as the result of exit or disposal activities. Excludes payments associated with a discontinued operation or an asset retirement obligation.

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-Publisher FASB

-Name Accounting Standards Codification

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Variable Interest Entities - Narrative (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014 VIE	Apr. 01, 2014
Variable Interest Entity [Line Items]
Number of Variable Interest Entities not consolidated by equity holders	7		6
Number Of Variable Interest Entities Consolidated	6
Guarantor Obligations, Current Carrying Value	$ 75,000,000
Guarantor Obligations, Maximum Exposure, Undiscounted	10,267,000,000
Exelon Generation Co L L C [Member]
Variable Interest Entity [Line Items]
Equity Method Investment, Ownership Percentage		50.01%
Related Party Transaction Required Purchase Of Power Percentage	85.00%
Guarantor Obligations, Current Carrying Value	7,000,000
Related Party Purchase Of Nuclear Output By Third Party Percentage	49.99%
Payables to affiliates	110,000,000		107,000,000
Guarantor Obligations, Maximum Exposure, Undiscounted	7,365,000,000
Exelon Generation Co L L C [Member] \| Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Guarantor Obligations, Current Carrying Value				7,000,000
Exelon Generation Co L L C [Member] \| Variable Interest Entity, Primary Beneficiary [Member] \| Equity Method Investment Variable Interest Entities [Member]
Variable Interest Entity [Line Items]
Guarantor Obligations, Current Carrying Value	637,000,000
Baltimore Gas and Electric Company [Member]
Variable Interest Entity [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	264,000,000
Baltimore Gas and Electric Company [Member] \| RSB Bond Co LLC [Member]
Variable Interest Entity [Line Items]
Remittance of payments received from customers for rate stabilization to BondCo.	21,000,000	21,000,000
Constellation Energy Nuclear Group [Member]
Variable Interest Entity [Line Items]
Severance Benefits Obligations Balance				6,000,000
Severance Costs	2,000,000
Constellation Energy Nuclear Group [Member] \| Exelon Generation Co L L C [Member]
Variable Interest Entity [Line Items]
Due from Affiliates	288,000,000			400,000,000
Financial Guarantee [Member] \| Constellation Energy Nuclear Group [Member]
Variable Interest Entity [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted				165,000,000
Payment Guarantee [Member] \| Constellation Energy Nuclear Group [Member]
Variable Interest Entity [Line Items]
Payables to affiliates				$ 245,000,000