Consolidated Statements Of Income (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Operating Revenue
Power Delivery	$ 4,650		$ 5,114		$ 4,980
Pepco Energy Services	1,238		1,883		2,383
Other	32		42		39
Total Operating Revenue	5,920		7,039		7,402
Operating Expenses
Fuel and purchased energy	3,422		4,631		5,330
Other services cost of sales	172		140		85
Other operation and maintenance	914		884		819
Restructuring charge			30
Depreciation and amortization	426		393		349
Other taxes	451		434		368
Gain on early termination of finance leases held in trust	(39)
Deferred electric service costs	(63)		(108)		(161)
Impairment Losses					4
Effects of Pepco divestiture-related claims			11		(40)
Total Operating Expenses	5,283		6,415	[1],[2]	6,754
Operating Income	637		624		648
Other Income (Expenses)
Interest and dividend income	1				2
Interest expense	(254)		(306)		(340)
(Loss) gain from equity investments	(3)		(1)		2
Loss on extinguishment of debt			(189)
Impairment losses	(5)
Other income	33		22		16
Other expenses	(228)		(474)	[3]	(1)
Total Other Expenses	(228)		(474)		(321)
Income From Continuing Operations Before Income Tax Expense	409		150		327
Income Tax Expense Related to Continuing Operations	149	[4]	11		104
Net Income from Continuing Operations	260		139		223
Income Tax Expense	28		21		12
(Loss) Income from Discontinued Operations, net of Income Taxes	(3)		(107)		12
Net Income (Loss)	257		32		235
Basic and Diluted Share Information
Weighted average shares outstanding	226		224		221
Earnings per share of common stock from Continuing Operations	$ 1.15		$ 0.62		$ 1.01
(Loss) earnings per share of common stock from Discontinued Operations	$ (0.01)		$ (0.48)		$ 0.05
Basic and Diluted Earnings Per Share of Common Stock	$ 1.14		$ 0.14		$ 1.06
Potomac Electric Power Co [Member]
Operating Revenue
Total Operating Revenue	2,078		2,288		2,231
Operating Expenses
Purchased energy	893		1,152		1,223
Other operation and maintenance	420		354		328
Restructuring charge			15
Depreciation and amortization	171		162		145
Other taxes	382		364		302
Effects of Pepco divestiture-related claims			11		(40)
Total Operating Expenses	1,866		2,058		1,958
Operating Income	212		230		273
Other Income (Expenses)
Interest and dividend income			1		1
Interest expense	(94)		(98)		(100)
Other income	17		12		9
Other expenses					(1)
Total Other Expenses	(77)		(85)		(91)
Income From Continuing Operations Before Income Tax Expense	135		145		182
Income Tax Expense	36		37		76
Net Income (Loss)	99		108		106
Delmarva Power & Light Co/De [Member]
Operating Revenue
Electric	1,074		1,163		1,135
Natural Gas	230		237		268
Total Operating Revenue	1,304		1,400		1,403
Operating Expenses
Purchased energy	635		740		751
Gas purchased	155		164		193
Other operation and maintenance	239		255		238
Restructuring charge			8
Depreciation and amortization	89		83		76
Other taxes	37		37		35
Total Operating Expenses	1,155		1,287		1,293
Operating Income	149		113		110
Other Income (Expenses)
Interest and dividend income					1
Interest expense	(44)		(44)		(44)
Other income	8		7		1
Total Other Expenses	(36)		(37)		(42)
Income From Continuing Operations Before Income Tax Expense	113		76		68
Income Tax Expense	42		31		16
Net Income (Loss)	71		45		52
Atlantic City Electric Co [Member]
Operating Revenue
Total Operating Revenue	1,268		1,430		1,351
Operating Expenses
Purchased energy	807		1,030		1,076
Other operation and maintenance	226		204		190
Restructuring charge			6
Depreciation and amortization	134		112		102
Other taxes	25		26		21
Deferred electric service costs	(63)		(108)		(161)
Total Operating Expenses	1,129		1,270		1,228
Operating Income	139		160		123
Other Income (Expenses)
Interest expense	(69)		(65)		(67)
Other income	2		1		2
Total Other Expenses	(67)		(64)		(65)
Income From Continuing Operations Before Income Tax Expense	72		96		58
Income Tax Expense	33		43		17
Net Income (Loss)	$ 39		$ 53		$ 41

[1] Includes restructuring charges of $14 million and $16 million in the third and fourth quarters, respectively.

[2] Includes expenses of $2 million and $9 million in the second and third quarters, respectively, related to the effects of Pepco divestiture-related claims.

[3] Includes debt extinguishment costs of $135 million and $54 million in the third and fourth quarters, respectively.

[4] Includes tax benefits of $14 million in the second quarter primarily associated with an interest benefit related to federal tax liabilities and a $22 million reversal of previously recognized tax benefits in the second quarter associated with the early termination of cross-border energy leases held in trust.