Consolidated Statements Of Cash Flows (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
OPERATING ACTIVITIES
Net (Loss) Income	$ (430)	$ 68
Income from discontinued operations		(5)
Adjustments to reconcile net (loss) income to net cash from operating activities:
Depreciation and amortization	112	110
Non-cash rents from cross-border energy lease investments	(5)	(13)
Non-cash charge to reduce carrying value of PHI's cross-border energy lease investments	373
Deferred income taxes	(496)	259
Other	(3)	(5)
Changes in:
Accounts receivable	(3)	78
Inventories	3
Prepaid expenses	10	8
Regulatory assets and liabilities, net	(6)	(37)
Accounts payable and accrued liabilities	(63)	(60)
Pension contributions	(60)	(200)
Pension benefit obligation, excluding contributions	14	15
Cash collateral related to derivative activities	17	20
Income tax-related prepayments, receivables and payables	604	(247)
Deposit made to taxing authority	(242)
Interest accrued	37	33
Other assets and liabilities	(5)	(2)
Net assets held for sale	(3)	1
Net Cash (Used By) From Operating Activities	(146)	23
INVESTING ACTIVITIES
Investment in property, plant and equipment	(296)	(291)
Department of Energy capital reimbursement awards received	1	7
Changes in restricted cash equivalents	2	1
Net other investing activities	(3)	2
Net Cash Used By Investing Activities	(296)	(281)
FINANCING ACTIVITIES
Dividends paid on common stock	(67)	(61)
Common stock issued for the Dividend Reinvestment Plan and employee-related compensation	15	17
Issuances of common stock	324
Issuances of long-term debt	250
Reacquisitions of long-term debt	(10)	(9)
Issuances of short-term debt, net	26	253
Issuance of term loan	250
Repayment of term loan	(200)
Cost of issuances	(16)	(3)
Net other financing activities	(30)	16
Net Cash From (Used By) Financing Activities	542	213
Net Increase (Decrease) in Cash and Cash Equivalents	100	(45)
Cash and Cash Equivalents at Beginning of Period	25	109
CASH AND CASH EQUIVALENTS AT END OF PERIOD	125	64
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Cash received for income taxes, net	(1)
Potomac Electric Power Co [Member]
OPERATING ACTIVITIES
Net (Loss) Income	23	24
Adjustments to reconcile net (loss) income to net cash from operating activities:
Depreciation and amortization	47	47
Deferred income taxes	26	127
Changes in:
Accounts receivable	(2)	35
Inventories	(2)	(4)
Prepaid expenses	3	4
Regulatory assets and liabilities, net	(9)	(14)
Accounts payable and accrued liabilities	(14)	(7)
Pension contributions		(85)
Pension benefit obligation, excluding contributions	4	6
Income tax-related prepayments, receivables and payables	(60)	(139)
Interest accrued	21	19
Other assets and liabilities		(3)
Net Cash (Used By) From Operating Activities	37	10
INVESTING ACTIVITIES
Investment in property, plant and equipment	(125)	(158)
Department of Energy capital reimbursement awards received	1	6
Net other investing activities	(3)	2
Net Cash Used By Investing Activities	(127)	(150)
FINANCING ACTIVITIES
Capital contribution from Parent	175
Issuances of long-term debt	250
(Reacquisitions) Issuances of short-term debt, net	(231)	130
Cost of issuances	(4)	(3)
Net other financing activities	(12)	8
Net Cash From (Used By) Financing Activities	178	135
Net Increase (Decrease) in Cash and Cash Equivalents	88	(5)
Cash and Cash Equivalents at Beginning of Period	9	12
CASH AND CASH EQUIVALENTS AT END OF PERIOD	97	7
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Cash received for income taxes, net		1
Delmarva Power & Light Co/De [Member]
OPERATING ACTIVITIES
Net (Loss) Income	26	21
Adjustments to reconcile net (loss) income to net cash from operating activities:
Depreciation and amortization	25	24
Deferred income taxes	17	41
Changes in:
Accounts receivable	(16)	16
Inventories	5	4
Regulatory assets and liabilities, net	5	(7)
Accounts payable and accrued liabilities	(9)	(8)
Pension contributions	(10)	(85)
Income tax-related prepayments, receivables and payables	1	(31)
Interest accrued	9	6
Other assets and liabilities	1	4
Net Cash (Used By) From Operating Activities	54	(15)
INVESTING ACTIVITIES
Investment in property, plant and equipment	(83)	(69)
Net other investing activities	1	(1)
Net Cash Used By Investing Activities	(82)	(70)
FINANCING ACTIVITIES
Issuances of short-term debt, net	38	87
Net other financing activities	(6)	(3)
Net Cash From (Used By) Financing Activities	32	84
Net Increase (Decrease) in Cash and Cash Equivalents	4	(1)
Cash and Cash Equivalents at Beginning of Period	6	5
CASH AND CASH EQUIVALENTS AT END OF PERIOD	10	4
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Cash received for income taxes, net
Atlantic City Electric Co [Member]
OPERATING ACTIVITIES
Net (Loss) Income	9	2
Adjustments to reconcile net (loss) income to net cash from operating activities:
Depreciation and amortization	31	28
Deferred income taxes	2	72
Changes in:
Accounts receivable	1	17
Inventories		(1)
Regulatory assets and liabilities, net	(1)	(16)
Accounts payable and accrued liabilities		(8)
Pension contributions	(30)	(30)
Income tax-related prepayments, receivables and payables	3	(63)
Other assets and liabilities	8	10
Net Cash (Used By) From Operating Activities	23	11
INVESTING ACTIVITIES
Investment in property, plant and equipment	(74)	(53)
Department of Energy capital reimbursement awards received		1
Net other investing activities	(2)
Net Cash Used By Investing Activities	(76)	(52)
FINANCING ACTIVITIES
Reacquisitions of long-term debt	(10)	(9)
Issuances of short-term debt, net	75
Net other financing activities	(8)	8
Net Cash From (Used By) Financing Activities	57	(1)
Net Increase (Decrease) in Cash and Cash Equivalents	4	(42)
Cash and Cash Equivalents at Beginning of Period	6	91
CASH AND CASH EQUIVALENTS AT END OF PERIOD	10	49
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Cash received for income taxes, net