Consolidated Balance Sheets (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
CURRENT ASSETS
Cash and cash equivalents	$ 58	$ 25
Restricted cash equivalents	15	10
Accounts receivable, less allowance for uncollectible accounts	844	804
Inventories	169	153
Prepayments of income taxes	41	59
Deferred income tax assets, net	37	28
Income taxes receivable	225	69
Prepaid expenses and other	74	81
Assets held for disposition	2	38
Total Current Assets	1,465	1,267
INVESTMENTS AND OTHER ASSETS
Goodwill	1,407	1,407
Regulatory assets	2,316	2,614
Income taxes receivable	64	217
Restricted cash equivalents	14	17
Assets and accrued interest related to uncertain tax positions	9	18
Derivative assets	4	8
Other	158	163
Assets held for disposition		1,237
Total Investments and Other Assets	3,972	5,681
PROPERTY, PLANT AND EQUIPMENT
Property, plant and equipment	14,277	13,625
Accumulated depreciation	(4,802)	(4,779)
Net Property, Plant and Equipment	9,475	8,846
TOTAL ASSETS	14,912	15,794
CURRENT LIABILITIES
Short-term debt	404	965
Current portion of long-term debt and project funding	695	569
Accounts payable and accrued liabilities	492	553
Capital lease obligations due within one year	9	8
Taxes accrued	50	75
Interest accrued	83	47
Liabilities and accrued interest related to uncertain tax positions	378	9
Derivative liabilities		4
Other	263	272
Liabilities associated with assets held for disposition	4	41
Total Current Liabilities	2,378	2,543
DEFERRED CREDITS
Regulatory liabilities	461	501
Deferred income tax liabilities, net	2,847	3,208
Investment tax credits	18	20
Pension benefit obligation	310	449
Other postretirement benefit obligations	255	454
Liabilities and accrued interest related to uncertain tax positions	29	15
Derivative liabilities	14	11
Other	192	191
Liabilities associated with assets held for disposition		2
Total Deferred Credits	4,126	4,851
LONG-TERM LIABILITIES
Long-term debt	3,805	3,648
Transition bonds issued by ACE Funding	226	256
Long-term project funding	10	12
Capital lease obligations	65	70
Total Long-Term Liabilities	4,106	3,986
COMMITMENTS AND CONTINGENCIES
EQUITY
Common stock	2	2
Premium on stock and other capital contributions	3,734	3,383
Accumulated other comprehensive loss	(40)	(48)
Retained earnings	606	1,077
Total Equity	4,302	4,414
TOTAL LIABILITIES AND EQUITY	14,912	15,794
Potomac Electric Power Co [Member]
CURRENT ASSETS
Cash and cash equivalents	8	9
Restricted cash equivalents	3
Accounts receivable, less allowance for uncollectible accounts	365	318
Inventories	72	69
Prepayments of income taxes	9	9
Income taxes receivable	101	31
Prepaid expenses and other	36	25
Total Current Assets	594	461
INVESTMENTS AND OTHER ASSETS
Regulatory assets	536	487
Prepaid pension expense	337	353
Investment in trust	33	31
Income taxes receivable	35	102
Other	63	59
Total Investments and Other Assets	1,004	1,032
PROPERTY, PLANT AND EQUIPMENT
Property, plant and equipment	7,164	6,850
Accumulated depreciation	(2,730)	(2,705)
Net Property, Plant and Equipment	4,434	4,145
TOTAL ASSETS	6,032	5,638
CURRENT LIABILITIES
Short-term debt	32	231
Current portion of long-term debt and project funding	375	200
Accounts payable and accrued liabilities	217	214
Accounts payable due to associated companies	31	41
Capital lease obligations due within one year	9	8
Taxes accrued	30	58
Interest accrued	39	17
Liabilities and accrued interest related to uncertain tax positions	25
Customer deposits	47	48
Other	59	58
Total Current Liabilities	864	875
DEFERRED CREDITS
Regulatory liabilities	141	141
Deferred income tax liabilities, net	1,343	1,219
Investment tax credits	3	4
Other postretirement benefit obligations	68	66
Liabilities and accrued interest related to uncertain tax positions	10	53
Other	65	66
Total Deferred Credits	1,630	1,549
LONG-TERM LIABILITIES
Long-term debt	1,575	1,501
Capital lease obligations	65	70
Total Long-Term Liabilities	1,640	1,571
COMMITMENTS AND CONTINGENCIES
EQUITY
Common stock
Premium on stock and other capital contributions	930	755
Retained earnings	968	888
Total Equity	1,898	1,643
TOTAL LIABILITIES AND EQUITY	6,032	5,638
Delmarva Power & Light Co/De [Member]
CURRENT ASSETS
Cash and cash equivalents	4	6
Accounts receivable, less allowance for uncollectible accounts	175	201
Inventories	63	53
Prepayments of income taxes	10	10
Income taxes receivable	5	10
Assets and accrued interest related to uncertain tax positions	18
Prepaid expenses and other	22	20
Total Current Assets	297	300
INVESTMENTS AND OTHER ASSETS
Goodwill	8	8
Regulatory assets	303	288
Prepaid pension expense	231	232
Assets and accrued interest related to uncertain tax positions	3	20
Other	13	12
Total Investments and Other Assets	558	560
PROPERTY, PLANT AND EQUIPMENT
Property, plant and equipment	3,592	3,422
Accumulated depreciation	(1,012)	(1,000)
Net Property, Plant and Equipment	2,580	2,422
TOTAL ASSETS	3,435	3,282
CURRENT LIABILITIES
Short-term debt	255	137
Current portion of long-term debt and project funding	250	250
Accounts payable and accrued liabilities	87	125
Accounts payable due to associated companies	21	20
Taxes accrued	6	4
Interest accrued	15	6
Derivative liabilities		4
Other	66	61
Total Current Liabilities	700	607
DEFERRED CREDITS
Regulatory liabilities	238	258
Deferred income tax liabilities, net	748	697
Investment tax credits	5	5
Other postretirement benefit obligations	25	22
Other	36	41
Total Deferred Credits	1,052	1,023
LONG-TERM LIABILITIES
Long-term debt	667	667
COMMITMENTS AND CONTINGENCIES
EQUITY
Common stock
Premium on stock and other capital contributions	407	407
Retained earnings	609	578
Total Equity	1,016	985
TOTAL LIABILITIES AND EQUITY	3,435	3,282
Atlantic City Electric Co [Member]
CURRENT ASSETS
Cash and cash equivalents	6	6
Restricted cash equivalents	12	10
Accounts receivable, less allowance for uncollectible accounts	215	192
Inventories	32	30
Prepayments of income taxes	17	27
Income taxes receivable	111	5
Assets and accrued interest related to uncertain tax positions	14
Prepaid expenses and other	28	11
Total Current Assets	435	281
INVESTMENTS AND OTHER ASSETS
Regulatory assets	603	694
Prepaid pension expense	109	88
Income taxes receivable	27	133
Restricted cash equivalents	14	17
Assets and accrued interest related to uncertain tax positions	6	12
Derivative assets	4	8
Other	12	12
Total Investments and Other Assets	775	964
PROPERTY, PLANT AND EQUIPMENT
Property, plant and equipment	2,861	2,771
Accumulated depreciation	(748)	(787)
Net Property, Plant and Equipment	2,113	1,984
TOTAL ASSETS	3,323	3,229
CURRENT LIABILITIES
Short-term debt	117	133
Current portion of long-term debt and project funding	48	108
Accounts payable and accrued liabilities	129	147
Accounts payable due to associated companies	12	14
Taxes accrued	11	10
Interest accrued	19	15
Customer deposits	25	25
Other	20	22
Total Current Liabilities	381	474
DEFERRED CREDITS
Regulatory liabilities	82	102
Deferred income tax liabilities, net	815	766
Investment tax credits	6	6
Other postretirement benefit obligations	36	34
Derivative liabilities	14	11
Other	17	18
Total Deferred Credits	970	937
LONG-TERM LIABILITIES
Long-term debt	853	760
Transition bonds issued by ACE Funding	226	256
Total Long-Term Liabilities	1,079	1,016
COMMITMENTS AND CONTINGENCIES
EQUITY
Common stock	26	26
Premium on stock and other capital contributions	651	576
Retained earnings	216	200
Total Equity	893	802
TOTAL LIABILITIES AND EQUITY	$ 3,323	$ 3,229