Consolidated Statements Of (Loss) Income (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Operating Revenue
Power Delivery	$ 1,124	$ 1,055
Pepco Energy Services	97	178
Other	(369)	9
Total Operating Revenue	852	1,242
Operating Expenses
Fuel and purchased energy	600	641
Other services cost of sales	40	47
Other operation and maintenance	230	224
Depreciation and amortization	112	110
Other taxes	105	104
Deferred electric service costs	1	(15)
Total Operating Expenses	1,088	1,111
Operating (Loss) Income	(236)	131
Other Income (Expenses)
Interest expense	(67)	(65)
Other income	8	8
Total Other Expenses	(59)	(57)
(Loss) Income from Continuing Operations Before Income Tax Expense (Benefit)	(295)	74
Income Tax Expense Related to Continuing Operations	135	11
Net (Loss) Income from Continuing Operations	(430)	63
Income from Discontinued Operations, Net of Income Taxes		5
Net (Loss) Income	(430)	68
Basic and Diluted Earnings per Share Information
Weighted average shares outstanding - Basic	237	228
Weighted average shares outstanding - Diluted	237	228
(Loss) earnings per share of common stock from Continuing Operations - Basic and Diluted	$ (1.82)	$ 0.28
Earnings per share of common stock from Discontinued Operations - Basic and Diluted		$ 0.02
Basic and Diluted (loss) earnings per share	$ (1.82)	$ 0.30
Potomac Electric Power Co [Member]
Operating Revenue
Total Operating Revenue	477	465
Operating Expenses
Purchased energy	192	185
Other operation and maintenance	102	103
Depreciation and amortization	47	47
Other taxes	89	90
Total Operating Expenses	430	425
Operating (Loss) Income	47	40
Other Income (Expenses)
Interest expense	(26)	(25)
Other income	4	4
Total Other Expenses	(22)	(21)
(Loss) Income from Continuing Operations Before Income Tax Expense (Benefit)	25	19
Income Tax Expense Related to Continuing Operations	2	(5)
Income Tax Expense (Benefit)	2	(5)
Net (Loss) Income	23	24
Delmarva Power & Light Co/De [Member]
Operating Revenue
Electric	285	259
Natural gas	85	74
Total Operating Revenue	370	333
Operating Expenses
Purchased energy	159	143
Gas purchased	54	49
Other operation and maintenance	69	65
Depreciation and amortization	25	24
Other taxes	10	9
Total Operating Expenses	317	290
Operating (Loss) Income	53	43
Other Income (Expenses)
Interest expense	(13)	(11)
Other income	2	3
Total Other Expenses	(11)	(8)
(Loss) Income from Continuing Operations Before Income Tax Expense (Benefit)	42	35
Income Tax Expense Related to Continuing Operations	16	14
Income Tax Expense (Benefit)	16	14
Net (Loss) Income	26	21
Atlantic City Electric Co [Member]
Operating Revenue
Total Operating Revenue	277	256
Operating Expenses
Purchased energy	157	166
Other operation and maintenance	61	56
Depreciation and amortization	31	28
Other taxes	4	4
Deferred electric service costs	1	(15)
Total Operating Expenses	254	239
Operating (Loss) Income	23	17
Other Income (Expenses)
Interest expense	(17)	(17)
Other income		1
Total Other Expenses	(17)	(16)
(Loss) Income from Continuing Operations Before Income Tax Expense (Benefit)	6	1
Income Tax Expense (Benefit)	(3)	(1)
Net (Loss) Income	$ 9	$ 2