Consolidated Balance Sheets (USD $) In Millions, unless otherwise specified	Dec. 31, 2011		Dec. 31, 2010
CURRENT ASSETS
Cash and cash equivalents	$ 109		$ 20
Restricted cash equivalents	11		11
Accounts receivable, less allowance for uncollectible accounts	929		1,027
Inventories	132		126
Derivative assets	5		45
Prepayments of income taxes	74		276
Deferred income tax assets, net	59		90
Prepaid expenses and other	120		51
Conectiv Energy assets held for sale			111
Total Current Assets	1,439		1,757
INVESTMENTS AND OTHER ASSETS
Goodwill	1,407		1,407
Regulatory assets	2,196		1,915
Investment in finance leases held in trust	1,349	[1]	1,423	[1]
Income taxes receivable	84		114
Restricted cash equivalents	15		5
Assets and accrued interest related to uncertain tax positions	37		11
Other	163		169
Conectiv Energy assets held for sale			6
Total Investments and Other Assets	5,251		5,050
PROPERTY, PLANT AND EQUIPMENT
Property, plant and equipment	12,855		12,120
Accumulated depreciation	(4,635)		(4,447)
Net Property, Plant and Equipment	8,220		7,673
TOTAL ASSETS	14,910		14,480
CURRENT LIABILITIES
Short-term debt	732		534
Current portion of long-term debt and project funding	112		75
Accounts payable and accrued liabilities	549		587
Capital lease obligations due within one year	8		8
Taxes accrued	110		96
Interest accrued	47		45
Liabilities and accrued interest related to uncertain tax positions	3		3
Derivative liabilities	26		66
Other	274		321
Liabilities associated with Conectiv Energy assets held for sale			62
Total Current Liabilities	1,861		1,797
DEFERRED CREDITS
Regulatory liabilities	526		528
Deferred income taxes, net	2,863		2,714
Investment tax credits	22		26
Pension benefit obligation	424		332
Other postretirement benefit obligations	469		429
Income taxes payable			2
Liabilities and accrued interest related to uncertain tax positions	32		148
Derivative liabilities	6		21
Other	191		175
Liabilities associated with Conectiv Energy assets held for sale			10
Total Deferred Credits	4,533		4,385
LONG-TERM LIABILITIES
Long-term debt	3,794		3,629
Transition bonds issued by ACE Funding	295		332
Long-term project funding	13		15
Capital lease obligations	78		86
Total Long-Term Liabilities	4,180		4,062
COMMITMENTS AND CONTINGENCIES
EQUITY
Common stock	2		2
Premium on stock and other capital contributions	3,325		3,275
Accumulated other comprehensive loss	(63)		(106)
Retained earnings	1,072		1,059
Total Shareholders' Equity	4,336		4,230
Non-controlling interest			6
Total Equity	4,336		4,236
TOTAL LIABILITIES AND EQUITY	14,910		14,480
Potomac Electric Power Co [Member]
CURRENT ASSETS
Cash and cash equivalents	12		88
Accounts receivable, less allowance for uncollectible accounts	339		373
Inventories	50		44
Prepayments of income taxes	7		95
Income taxes receivable	31		37
Prepaid expenses and other	32		34
Total Current Assets	471		671
INVESTMENTS AND OTHER ASSETS
Regulatory assets	299		191
Prepaid pension expense	289		274
Investment in trust	31		25
Income taxes receivable	24		34
Other	55		57
Total Investments and Other Assets	698		581
PROPERTY, PLANT AND EQUIPMENT
Property, plant and equipment	6,578		6,185
Accumulated depreciation	(2,704)		(2,609)
Net Property, Plant and Equipment	3,874		3,576
TOTAL ASSETS	5,043		4,828
CURRENT LIABILITIES
Short-term debt	74
Accounts payable and accrued liabilities	209		194
Accounts payable due to associated companies	57		75
Capital lease obligations due within one year	8		8
Taxes accrued	63		62
Interest accrued	17		18
Other	110		119
Total Current Liabilities	538		476
DEFERRED CREDITS
Regulatory liabilities	169		147
Deferred income taxes, net	1,039		958
Investment tax credits	5		7
Other postretirement benefit obligations	66		67
Income taxes payable			3
Liabilities and accrued interest related to uncertain tax positions	38		52
Other	68		64
Total Deferred Credits	1,385		1,298
LONG-TERM LIABILITIES
Long-term debt	1,540		1,540
Capital lease obligations	78		86
Total Long-Term Liabilities	1,618		1,626
COMMITMENTS AND CONTINGENCIES
EQUITY
Premium on stock and other capital contributions	705		705
Retained earnings	797		723
Total Shareholders' Equity	1,502		1,428
TOTAL LIABILITIES AND EQUITY	5,043		4,828
Delmarva Power & Light Co/De [Member]
CURRENT ASSETS
Cash and cash equivalents	5		69
Accounts receivable, less allowance for uncollectible accounts	186		212
Inventories	44		41
Prepayments of income taxes	14		62
Prepaid expenses and other	28		22
Total Current Assets	277		406
INVESTMENTS AND OTHER ASSETS
Goodwill	8		8
Regulatory assets	227		242
Prepaid pension expense	162		139
Other	23		21
Total Investments and Other Assets	420		410
PROPERTY, PLANT AND EQUIPMENT
Property, plant and equipment	3,188		3,000
Accumulated depreciation	(926)		(901)
Net Property, Plant and Equipment	2,262		2,099
TOTAL ASSETS	2,959		2,915
CURRENT LIABILITIES
Short-term debt	152		105
Current portion of long-term debt and project funding	66		35
Accounts payable and accrued liabilities	92		98
Accounts payable due to associated companies	21		34
Taxes accrued	11		6
Interest accrued	6		7
Derivative liabilities	12		15
Other	59		73
Total Current Liabilities	419		373
DEFERRED CREDITS
Regulatory liabilities	297		310
Deferred income taxes, net	615		561
Investment tax credits	6		7
Other postretirement benefit obligations	22		22
Liabilities and accrued interest related to uncertain tax positions	9		24
Derivative liabilities	3		8
Other	37		39
Total Deferred Credits	989		971
LONG-TERM LIABILITIES
Long-term debt	699		730
COMMITMENTS AND CONTINGENCIES
EQUITY
Premium on stock and other capital contributions	347		347
Retained earnings	505		494
Total Shareholders' Equity	852		841
TOTAL LIABILITIES AND EQUITY	2,959		2,915
Atlantic City Electric Co [Member]
CURRENT ASSETS
Cash and cash equivalents	91		4
Restricted cash equivalents	11		11
Accounts receivable, less allowance for uncollectible accounts	185		212
Inventories	25		17
Prepayments of income taxes	26		55
Income taxes receivable	5		25
Prepaid expenses and other	16		9
Total Current Assets	359		333
INVESTMENTS AND OTHER ASSETS
Regulatory assets	662		667
Prepaid pension expense	71		51
Income taxes receivable	61		59
Restricted cash equivalents	15		5
Assets and accrued interest related to uncertain tax positions	42		38
Other	14		11
Total Investments and Other Assets	865		831
PROPERTY, PLANT AND EQUIPMENT
Property, plant and equipment	2,548		2,443
Accumulated depreciation	(766)		(729)
Net Property, Plant and Equipment	1,782		1,714
TOTAL ASSETS	3,006		2,878
CURRENT LIABILITIES
Short-term debt	23		181
Current portion of long-term debt and project funding	37		35
Accounts payable and accrued liabilities	117		120
Accounts payable due to associated companies	14		29
Taxes accrued	10		7
Interest accrued	15		13
Other	45		41
Total Current Liabilities	261		426
DEFERRED CREDITS
Regulatory liabilities	60		71
Deferred income taxes, net	698		659
Investment tax credits	7		8
Other postretirement benefit obligations	31		27
Other	20		13
Total Deferred Credits	816		778
LONG-TERM LIABILITIES
Long-term debt	832		633
Transition bonds issued by ACE Funding	295		332
Total Long-Term Liabilities	1,127		965
COMMITMENTS AND CONTINGENCIES
REDEEMABLE SERIAL PREFERRED STOCK			6
EQUITY
Common stock	26		26
Premium on stock and other capital contributions	576		516
Retained earnings	200		161
Total Shareholders' Equity	802		703
TOTAL LIABILITIES AND EQUITY	$ 3,006		$ 2,878

[1] Excludes the credit ratings of collateral posted by the lessees in these transactions.