Consolidated Statements Of Cash Flows (USD $)	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
OPERATING ACTIVITIES
Net Income	$ 68,000,000	$ 64,000,000
(Income) loss from discontinued operations		(2,000,000)
Adjustments to reconcile net income (loss) to net cash from operating activities:
Depreciation and amortization	110,000,000	105,000,000
Non-cash rents from cross-border energy lease investments	(13,000,000)	(14,000,000)
Deferred income taxes	259,000,000	90,000,000
Other	(4,000,000)	(4,000,000)
Changes in:
Accounts receivable	78,000,000	87,000,000
Inventories	3,000,000	10,000,000
Prepaid expenses		10,000,000
Regulatory assets and liabilities, net	(37,000,000)	11,000,000
Accounts payable and accrued liabilities	(60,000,000)	(126,000,000)
Pension contributions	(200,000,000)	(110,000,000)
Pension benefit obligation, excluding contributions	15,000,000	16,000,000
Cash collateral related to derivative activities	20,000,000	31,000,000
Taxes accrued	(247,000,000)	(49,000,000)
Interest accrued	33,000,000	31,000,000
Other assets and liabilities	(2,000,000)	16,000,000
Conectiv Energy net assets held for sale		31,000,000
Net Cash From Operating Activities	23,000,000	197,000,000
INVESTING ACTIVITIES
Investment in property, plant and equipment	(291,000,000)	(171,000,000)
Department of Energy capital reimbursement awards received	7,000,000	9,000,000
Changes in restricted cash equivalents	1,000,000	(2,000,000)
Net other investing activities	2,000,000
Net Cash (Used By) From Investing Activities	(281,000,000)	(164,000,000)
FINANCING ACTIVITIES
Dividends paid on common stock	(61,000,000)	(61,000,000)
Common stock issued for the Dividend Reinvestment Plan and employee-related compensation	17,000,000	14,000,000
Redemption of preferred stock of subsidiaries		(6,000,000)
Reacquisitions of long-term debt	(9,000,000)	(9,000,000)
(Repayments) issuances of short-term debt, net	253,000,000	33,000,000
Cost of issuances	(3,000,000)
Net other financing activities	16,000,000	(7,000,000)
Net Cash (Used By) From Financing Activities	213,000,000	(36,000,000)
Net Increase (Decrease) in Cash and Cash Equivalents	(45,000,000)	(3,000,000)
Cash and Cash Equivalents at Beginning of Period	109,000,000	21,000,000
Cash and Cash Equivalents at Beginning of Period	109,000,000
CASH AND CASH EQUIVALENTS AT END OF PERIOD	64,000,000	18,000,000
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Cash (received) paid for income taxes		2,000,000
Potomac Electric Power Co [Member]
OPERATING ACTIVITIES
Net Income	24,000,000	18,000,000
Adjustments to reconcile net income (loss) to net cash from operating activities:
Depreciation and amortization	47,000,000	42,000,000
Deferred income taxes	127,000,000	26,000,000
Changes in:
Accounts receivable	35,000,000	28,000,000
Inventories	(4,000,000)	(4,000,000)
Regulatory assets and liabilities, net	(14,000,000)	(4,000,000)
Accounts payable and accrued liabilities	(7,000,000)	(33,000,000)
Pension contributions	(85,000,000)	(40,000,000)
Taxes accrued	(139,000,000)	50,000,000
Interest accrued	19,000,000	19,000,000
Other assets and liabilities	4,000,000	16,000,000
Net Cash From Operating Activities	7,000,000	118,000,000
INVESTING ACTIVITIES
Investment in property, plant and equipment	(158,000,000)	(97,000,000)
Department of Energy capital reimbursement awards received	6,000,000	8,000,000
Net other investing activities	2,000,000	(1,000,000)
Net Cash (Used By) From Investing Activities	(150,000,000)	(90,000,000)
FINANCING ACTIVITIES
(Repayments) issuances of short-term debt, net	130,000,000
Net other financing activities	8,000,000
Net Cash (Used By) From Financing Activities	138,000,000
Net Increase (Decrease) in Cash and Cash Equivalents	(5,000,000)	28,000,000
Cash and Cash Equivalents at Beginning of Period	12,000,000	88,000,000
CASH AND CASH EQUIVALENTS AT END OF PERIOD	7,000,000	116,000,000
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Cash (received) paid for income taxes	1,000,000	(70,000,000)
Delmarva Power & Light Co/De [Member]
OPERATING ACTIVITIES
Net Income	21,000,000	23,000,000
Adjustments to reconcile net income (loss) to net cash from operating activities:
Depreciation and amortization	24,000,000	22,000,000
Deferred income taxes	41,000,000	18,000,000
Changes in:
Accounts receivable	16,000,000	6,000,000
Inventories	4,000,000	9,000,000
Regulatory assets and liabilities, net	(7,000,000)	18,000,000
Accounts payable and accrued liabilities	(8,000,000)	(34,000,000)
Pension contributions	(85,000,000)	(40,000,000)
Taxes accrued	(31,000,000)	(4,000,000)
Interest accrued	6,000,000	6,000,000
Other assets and liabilities	4,000,000	10,000,000
Net Cash From Operating Activities	(15,000,000)	34,000,000
INVESTING ACTIVITIES
Investment in property, plant and equipment	(69,000,000)	(41,000,000)
Net other investing activities	(1,000,000)	1,000,000
Net Cash (Used By) From Investing Activities	(70,000,000)	(40,000,000)
FINANCING ACTIVITIES
(Repayments) issuances of short-term debt, net	87,000,000
Net other financing activities	(3,000,000)
Net Cash (Used By) From Financing Activities	84,000,000
Net Increase (Decrease) in Cash and Cash Equivalents	(1,000,000)	(6,000,000)
Cash and Cash Equivalents at Beginning of Period	5,000,000	69,000,000
CASH AND CASH EQUIVALENTS AT END OF PERIOD	4,000,000	63,000,000
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Cash (received) paid for income taxes		4,000,000
Atlantic City Electric Co [Member]
OPERATING ACTIVITIES
Net Income	2,000,000	6,000,000
Adjustments to reconcile net income (loss) to net cash from operating activities:
Depreciation and amortization	28,000,000	33,000,000
Deferred income taxes	72,000,000	9,000,000
Changes in:
Accounts receivable	17,000,000	16,000,000
Inventories	(1,000,000)
Regulatory assets and liabilities, net	(16,000,000)	(3,000,000)
Accounts payable and accrued liabilities	(8,000,000)	(23,000,000)
Pension contributions	(30,000,000)	(30,000,000)
Taxes accrued	(63,000,000)	12,000,000
Interest accrued		3,000,000
Other assets and liabilities	10,000,000	10,000,000
Net Cash From Operating Activities	11,000,000	33,000,000
INVESTING ACTIVITIES
Investment in property, plant and equipment	(53,000,000)	(22,000,000)
Department of Energy capital reimbursement awards received	1,000,000	1,000,000
Net other investing activities		(3,000,000)
Net Cash (Used By) From Investing Activities	(52,000,000)	(24,000,000)
FINANCING ACTIVITIES
Redemption of preferred stock of subsidiaries		(6,000,000)
Reacquisitions of long-term debt	(9,000,000)	(9,000,000)
(Repayments) issuances of short-term debt, net		7,000,000
Net other financing activities	8,000,000	(1,000,000)
Net Cash (Used By) From Financing Activities	(1,000,000)	(9,000,000)
Net Increase (Decrease) in Cash and Cash Equivalents	(42,000,000)
Cash and Cash Equivalents at Beginning of Period	91,000,000	4,000,000
CASH AND CASH EQUIVALENTS AT END OF PERIOD	49,000,000	4,000,000
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Cash (received) paid for income taxes		$ (6,000,000)