After tax gain on sale of land.

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Impairment loss after tax.

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No definition available.

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- Definition

Long lived assets after impairment carrying value.

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No definition available.

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Long lived assets before impairment carrying value.

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No definition available.

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- Definition

Percentage of change in estimated cash flow does not impact on estimated fair value of assets.

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No definition available.

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- Definition

Percentage of increase decrease in discount rate assumptions.

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No definition available.

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- Definition

Period Of Option To Purchase Remaining Land

+ References

No definition available.

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- Definition

Pretax gain on sale of land.

+ References

No definition available.

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- Definition

Range of discount rates.

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No definition available.

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- Definition

Area of land held.

+ References

No definition available.

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- Definition

Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=51824106&loc=d3e2420-110228

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-Subparagraph (b)
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- Definition

The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
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-Name Accounting Standards Codification
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- Definition

Amount of minimum lease payments for capital leases due in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 840
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)
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Amount of minimum lease payments for capital leases due in the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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Amount of minimum lease payments for capital leases due in the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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Amount of minimum lease payments for capital leases due in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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- Definition

Amount of minimum lease payments for capital leases net of executory costs, which include amounts paid by the lessee to the lessor for insurance, maintenance and taxes.

+ References

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- Definition

Present value of minimum lease payments for capital leases net of executory costs, including amounts paid by the lessee to the lessor for insurance, maintenance and taxes.

+ References

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- Definition

The estimate of the lease property's economic value at the end of the direct financing lease term excluding any amounts guaranteed by either the lessee or a third-party.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 30
-Section 50
-Paragraph 4
-Subparagraph (a)(2)
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- Definition

A general description of the nature of the existing leasing arrangements of a lessor for all types of capital leases (sales-type, direct financing, leveraged) including, but not limited to: (1) unguaranteed residual values, if any, (2) restrictions imposed by lease arrangements; (3) unusual provisions or conditions; (4) contingent rentals, if any; and (5) lease expiration dates.

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- Definition

The total period end amount of plant in service and construction in progress net of accumulated depreciation for the utility's share of jointly owned electricity generation plant.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 980
-SubTopic 360
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 10.C)
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-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 10
-Section C

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- Definition

Carrying value of land held for sale.

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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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- Definition

Discloses the total purchase price of land option agreements that were not recorded.

+ References

No definition available.

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- Definition

The cash inflow from the sale of land held for investment; excludes sales of land held as inventory or productive use.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3179-108585

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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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Carrying amount of an option or options to acquire real property.

+ References

No definition available.

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Property, Plant and Equipment - Additional Information (Detail)				12 Months Ended
	Nov. 10, 2015 USD ($)	Oct. 16, 2015 USD ($) a	Jul. 02, 2015 USD ($) a	Dec. 31, 2015 USD ($) a	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Property, Plant and Equipment [Line Items]
Present value of future minimum lease payments				$ 152,000,000
Semi-annual payments				$ 8,000,000
Description of lease term				Over a 25-year period that began in December 1994
Guaranteed residual value due at end of lease term				$ 1
Approximate annual commitments, 2016				15,000,000
Approximate annual commitments, 2017				15,000,000
Approximate annual commitments, 2018				15,000,000
Approximate annual commitments, 2019				$ 16,000,000
Impairment losses					$ 81,000,000	$ 4,000,000
Long lived assets after impairment, carrying amount					$ 2,000,000
Percentage of change in the estimated cash flows					10.00%
Percentage of change in discount rate assumptions					1.00%
Minimum [Member]
Property, Plant and Equipment [Line Items]
Range of discount rates					10.00%
Maximum [Member]
Property, Plant and Equipment [Line Items]
Range of discount rates					16.00%
Pepco Energy Services [Member]
Property, Plant and Equipment [Line Items]
Impairment losses					$ 81,000,000
Impairment losses, after-tax					48,000,000
Long-lived assets before impairment, carrying amount					83,000,000
Buzzard Point [Member]
Property, Plant and Equipment [Line Items]
Area of land held as non-utility property \| a			3.5
Carrying value of land			$ 2,000,000
Sale price of land			$ 39,000,000
Gain on sale of land before tax	$ 37,000,000
Gain on sale of land after tax	22,000,000
No Ma [Member]
Property, Plant and Equipment [Line Items]
Area of land held as non-utility property \| a		3.8		1.8
Carrying value remaining portion of land				$ 4,000,000
Sale price of remaining portion of land				$ 13,000,000
Period to purchase remaining portion of land				90 days
No Ma [Member] \| Third Party Sale Agreement [Member]
Property, Plant and Equipment [Line Items]
Area of land held as non-utility property \| a		2
Carrying value of land		$ 5,000,000
Sale price of land		$ 14,000,000
Gain on sale of land before tax				$ 9,000,000
Gain on sale of land after tax				5,000,000
Subsidiaries [Member]
Property, Plant and Equipment [Line Items]
Jointly owned plant, net book value ownership				16,000,000	15,000,000
Impairment losses						4,000,000
Impairment losses, after-tax						$ 3,000,000
Potomac Electric Power Co [Member]
Property, Plant and Equipment [Line Items]
Present value of future minimum lease payments				152,000,000
Semi-annual payments				$ 8,000,000
Description of lease term				Over a 25-year period that began in December 1994
Guaranteed residual value due at end of lease term				$ 1
Approximate annual commitments, 2016				15,000,000
Approximate annual commitments, 2017				15,000,000
Approximate annual commitments, 2018				15,000,000
Approximate annual commitments, 2019				$ 16,000,000
Potomac Electric Power Co [Member] \| Buzzard Point [Member]
Property, Plant and Equipment [Line Items]
Area of land held as non-utility property \| a			3.5
Carrying value of land			$ 2,000,000
Sale price of land			$ 39,000,000
Gain on sale of land before tax	37,000,000
Gain on sale of land after tax	$ 22,000,000
Potomac Electric Power Co [Member] \| No Ma [Member]
Property, Plant and Equipment [Line Items]
Area of land held as non-utility property \| a				1.8
Carrying value remaining portion of land				$ 4,000,000
Sale price of remaining portion of land				$ 13,000,000
Period to purchase remaining portion of land				90 days
Potomac Electric Power Co [Member] \| No Ma [Member] \| Third Party Sale Agreement [Member]
Property, Plant and Equipment [Line Items]
Area of land held as non-utility property \| a		2.0
Carrying value of land		$ 5,000,000
Sale price of land		$ 14,000,000
Gain on sale of land before tax				$ 9,000,000
Gain on sale of land after tax				5,000,000
Conectiv Energy [Member]
Property, Plant and Equipment [Line Items]
Asset retirement obligation				7,000,000
Atlantic City Electric Co [Member]
Property, Plant and Equipment [Line Items]
Jointly owned plant, net book value ownership				$ 11,000,000	$ 11,000,000