Consolidated Balance Sheets (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
CURRENT ASSETS
Cash and cash equivalents	$ 64	$ 109
Restricted cash equivalents	10	11
Accounts receivable, less allowance for uncollectible accounts	843	929
Inventories	129	132
Derivative assets	6	5
Prepayments of income taxes	131	74
Deferred income tax assets, net	43	59
Prepaid expenses and other	122	120
Total Current Assets	1,348	1,439
INVESTMENTS AND OTHER ASSETS
Goodwill	1,407	1,407
Regulatory assets	2,215	2,196
Investment in finance leases held in trust	1,362	1,349
Income taxes receivable	217	84
Restricted cash equivalents	15	15
Assets and accrued interest related to uncertain tax positions	60	37
Other	165	163
Total Investments and Other Assets	5,441	5,251
PROPERTY, PLANT AND EQUIPMENT
Property, plant and equipment	13,080	12,855
Accumulated depreciation	(4,681)	(4,635)
Net Property, Plant and Equipment	8,399	8,220
TOTAL ASSETS	15,188	14,910
CURRENT LIABILITIES
Short-term debt	986	732
Current portion of long-term debt and project funding	114	112
Accounts payable and accrued liabilities	522	549
Capital lease obligations due within one year	8	8
Taxes accrued	99	110
Interest accrued	79	47
Liabilities and accrued interest related to uncertain tax positions	3	3
Derivative liabilities	25	26
Other	259	274
Total Current Liabilities	2,095	1,861
DEFERRED CREDITS
Regulatory liabilities	526	526
Deferred income taxes, net	3,119	2,863
Investment tax credits	22	22
Pension benefit obligation	232	424
Other postretirement benefit obligations	467	469
Liabilities and accrued interest related to uncertain tax positions	10	32
Derivative liabilities	2	6
Other	179	191
Total Deferred Credits	4,557	4,533
LONG-TERM LIABILITIES
Long-term debt	3,794	3,794
Transition bonds issued by ACE Funding	285	295
Long-term project funding	13	13
Capital lease obligations	78	78
Total Long-Term Liabilities	4,170	4,180
COMMITMENTS AND CONTINGENCIES
EQUITY
Common stock	2	2
Premium on stock and other capital contributions	3,340	3,325
Accumulated other comprehensive loss	(55)	(63)
Retained earnings	1,079	1,072
Total Equity	4,366	4,336
TOTAL LIABILITIES AND EQUITY	15,188	14,910
Potomac Electric Power Co [Member]
CURRENT ASSETS
Cash and cash equivalents	7	12
Accounts receivable, less allowance for uncollectible accounts	305	339
Inventories	54	50
Prepayments of income taxes	18	7
Income taxes receivable	31	31
Prepaid expenses and other	29	32
Total Current Assets	444	471
INVESTMENTS AND OTHER ASSETS
Regulatory assets	332	299
Prepaid pension expense	368	289
Investment in trust	30	31
Income taxes receivable	103	24
Other	63	55
Total Investments and Other Assets	896	698
PROPERTY, PLANT AND EQUIPMENT
Property, plant and equipment	6,691	6,578
Accumulated depreciation	(2,722)	(2,704)
Net Property, Plant and Equipment	3,969	3,874
TOTAL ASSETS	5,309	5,043
CURRENT LIABILITIES
Short-term debt	204	74
Accounts payable and accrued liabilities	200	209
Accounts payable due to associated companies	64	57
Capital lease obligations due within one year	8	8
Taxes accrued	51	63
Interest accrued	36	17
Other	111	110
Total Current Liabilities	674	538
DEFERRED CREDITS
Regulatory liabilities	173	169
Deferred income taxes, net	1,173	1,039
Investment tax credits	5	5
Other postretirement benefit obligations	67	66
Liabilities and accrued interest related to uncertain tax positions	5	38
Other	68	68
Total Deferred Credits	1,491	1,385
LONG-TERM LIABILITIES
Long-term debt	1,540	1,540
Capital lease obligations	78	78
Total Long-Term Liabilities	1,618	1,618
COMMITMENTS AND CONTINGENCIES
EQUITY
Common stock
Premium on stock and other capital contributions	705	705
Retained earnings	821	797
Total Equity	1,526	1,502
TOTAL LIABILITIES AND EQUITY	5,309	5,043
Delmarva Power & Light Co/De [Member]
CURRENT ASSETS
Cash and cash equivalents	4	5
Accounts receivable, less allowance for uncollectible accounts	170	186
Inventories	40	44
Prepayments of income taxes	32	14
Income taxes receivable	10	11
Prepaid expenses and other	14	17
Total Current Assets	270	277
INVESTMENTS AND OTHER ASSETS
Goodwill	8	8
Regulatory assets	222	227
Prepaid pension expense	243	162
Other	26	23
Total Investments and Other Assets	499	420
PROPERTY, PLANT AND EQUIPMENT
Property, plant and equipment	3,249	3,188
Accumulated depreciation	(936)	(926)
Net Property, Plant and Equipment	2,313	2,262
TOTAL ASSETS	3,082	2,959
CURRENT LIABILITIES
Short-term debt	238	152
Current portion of long-term debt and project funding	66	66
Accounts payable and accrued liabilities	84	92
Accounts payable due to associated companies	18	21
Taxes accrued	7	11
Interest accrued	12	6
Derivative liabilities	12	12
Other	59	59
Total Current Liabilities	496	419
DEFERRED CREDITS
Regulatory liabilities	292	297
Deferred income taxes, net	655	615
Investment tax credits	6	6
Other postretirement benefit obligations	23	22
Liabilities and accrued interest related to uncertain tax positions		9
Derivative liabilities		3
Other	38	37
Total Deferred Credits	1,014	989
LONG-TERM LIABILITIES
Total Long-Term Liabilities	699	699
COMMITMENTS AND CONTINGENCIES
EQUITY
Common stock
Premium on stock and other capital contributions	347	347
Retained earnings	526	505
Total Equity	873	852
TOTAL LIABILITIES AND EQUITY	3,082	2,959
Atlantic City Electric Co [Member]
CURRENT ASSETS
Cash and cash equivalents	49	91
Restricted cash equivalents	10	11
Accounts receivable, less allowance for uncollectible accounts	168	185
Inventories	25	25
Prepayments of income taxes	45	26
Income taxes receivable	5	5
Prepaid expenses and other	9	16
Total Current Assets	311	359
INVESTMENTS AND OTHER ASSETS
Regulatory assets	670	662
Prepaid pension expense	99	71
Income taxes receivable	133	61
Restricted cash equivalents	15	15
Assets and accrued interest related to uncertain tax positions	22	42
Other	12	14
Total Investments and Other Assets	951	865
PROPERTY, PLANT AND EQUIPMENT
Property, plant and equipment	2,592	2,548
Accumulated depreciation	(772)	(766)
Net Property, Plant and Equipment	1,820	1,782
TOTAL ASSETS	3,082	3,006
CURRENT LIABILITIES
Short-term debt	23	23
Current portion of long-term debt and project funding	38	37
Accounts payable and accrued liabilities	122	117
Accounts payable due to associated companies	14	14
Taxes accrued	17	10
Interest accrued	21	15
Other	41	45
Total Current Liabilities	276	261
DEFERRED CREDITS
Regulatory liabilities	62	60
Deferred income taxes, net	768	698
Investment tax credits	7	7
Other postretirement benefit obligations	31	31
Other	16	20
Total Deferred Credits	884	816
LONG-TERM LIABILITIES
Long-term debt	833	832
Transition bonds issued by ACE Funding	285	295
Total Long-Term Liabilities	1,118	1,127
COMMITMENTS AND CONTINGENCIES
EQUITY
Common stock	26	26
Premium on stock and other capital contributions	576	576
Retained earnings	202	200
Total Equity	804	802
TOTAL LIABILITIES AND EQUITY	$ 3,082	$ 3,006