Impairment loss after tax.

No definition available.

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- Definition

Income tax interest benefit on uncertain tax positions.

+ References

No definition available.

+ Details

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- Definition

Income tax interest expense on uncertain tax positions.

+ References

No definition available.

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- Definition

Interest Income

+ References

No definition available.

+ Details

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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 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

Reference 2: 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=8077374&loc=d3e2420-110228

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- Definition

Total costs of sales and operating expenses for the period.

+ References

+ Details

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- Definition

The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

+ References

+ Details

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- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

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- Definition

Amount of the cost of borrowed funds accounted for as interest expense.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6450988&loc=d3e26243-108391

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-04.9)

-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 9

-Article 9

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- Definition

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Article 5

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- Definition

Amount of increase (decrease) in the valuation allowance for a specified deferred tax asset.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 45

-Paragraph 20

-URI http://asc.fasb.org/extlink&oid=37586315&loc=d3e32123-109318

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Segment Information - Segment Financial Information for Continuing Operations (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Goodwill	$ 1,407us-gaap_Goodwill				$ 1,407us-gaap_Goodwill				$ 1,407us-gaap_Goodwill	$ 1,407us-gaap_Goodwill
Operating Revenue	1,118us-gaap_Revenues	1,313us-gaap_Revenues	1,117us-gaap_Revenues	1,330us-gaap_Revenues	1,091us-gaap_Revenues	1,344us-gaap_Revenues	1,051us-gaap_Revenues	1,180us-gaap_Revenues	4,878us-gaap_Revenues	4,666us-gaap_Revenues	4,625us-gaap_Revenues
Operating Expenses	1,004us-gaap_CostsAndExpenses	1,147us-gaap_CostsAndExpenses	966us-gaap_CostsAndExpenses	1,157us-gaap_CostsAndExpenses	936us-gaap_CostsAndExpenses	1,109us-gaap_CostsAndExpenses	906us-gaap_CostsAndExpenses	1,047us-gaap_CostsAndExpenses	4,274us-gaap_CostsAndExpenses	3,998us-gaap_CostsAndExpenses	4,084us-gaap_CostsAndExpenses
Interest Expense									268us-gaap_InterestExpense	273us-gaap_InterestExpense	256us-gaap_InterestExpense
Depreciation and amortization									549	473	454
Impairment losses									81us-gaap_AssetImpairmentCharges	4us-gaap_AssetImpairmentCharges	12us-gaap_AssetImpairmentCharges
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Operating Revenue									(7)	(9)	(9)
Operating Expenses									4	(31)	(34)
Interest Expense									41	44	35
Pepco Energy Services [Member]
Segment Reporting Information [Line Items]
Impairment losses									81	4	12
Impairment loss, after-tax									48	3	7
Pepco Energy Services' Retail Electric and Natural Gas Supply Businesses [Member]
Segment Reporting Information [Line Items]
Operating Revenue											9
Operating Segments [Member] \| Power Delivery [Member]
Segment Reporting Information [Line Items]
Goodwill	1,400				1,400				1,400	1,400	1,400
Operating Revenue									4,607	4,472	4,378
Operating Expenses									3,916	3,828	3,847
Interest Expense									226	228	219
Depreciation and amortization									511	439	416
Interest benefit on uncertain tax positions										12
Operating Segments [Member] \| Pepco Energy Services [Member]
Segment Reporting Information [Line Items]
Operating Revenue									278	203	256
Operating Expenses									354	201	271
Interest Expense									1	1	2
Depreciation and amortization									7	6	14
Intersegment [Member] \| Corporate and Other [Member]
Segment Reporting Information [Line Items]
Operating Revenue									(7)	(10)	(11)
Operating Expenses									(7)	(9)	(10)
Interest Expense									(4)	(5)	(18)
Depreciation and amortization									31	28	24
Interest expense on uncertain tax positions										66
Valuation allowances against deferred tax assets										101
Interest Income											$ (21)