Lessee - Supplemental Balance Sheet Information (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Supplemental Balance Sheet Information [Line Items]
Other current liabilities	$ 1,155	$ 766
Other deferred credits and other liabilities	1,967	1,573
Operating Lease, Liability	306	315
Other Noncurrent Assets [Member]
Supplemental Balance Sheet Information [Line Items]
Operating Lease, Right-of-Use Asset	265	271
Other Current Liabilities [Member]
Supplemental Balance Sheet Information [Line Items]
Other current liabilities	40	52
Other deferred credits and other liabilities [Member]
Supplemental Balance Sheet Information [Line Items]
Other deferred credits and other liabilities	266	263
Commonwealth Edison Co [Member]
Supplemental Balance Sheet Information [Line Items]
Other current liabilities	191	133
Other deferred credits and other liabilities	642	592
Operating Lease, Liability	2	5
Commonwealth Edison Co [Member] | Other Noncurrent Assets [Member]
Supplemental Balance Sheet Information [Line Items]
Operating Lease, Right-of-Use Asset	2	5
Commonwealth Edison Co [Member] | Other Current Liabilities [Member]
Supplemental Balance Sheet Information [Line Items]
Other current liabilities	2	2
Commonwealth Edison Co [Member] | Other deferred credits and other liabilities [Member]
Supplemental Balance Sheet Information [Line Items]
Other deferred credits and other liabilities	0	3
PECO Energy Co [Member]
Supplemental Balance Sheet Information [Line Items]
Other current liabilities	32	35
Other deferred credits and other liabilities	85	83
Operating Lease, Liability	1	1
PECO Energy Co [Member] | Other Noncurrent Assets [Member]
Supplemental Balance Sheet Information [Line Items]
Operating Lease, Right-of-Use Asset	1	1
PECO Energy Co [Member] | Other Current Liabilities [Member]
Supplemental Balance Sheet Information [Line Items]
Other current liabilities	0	0
PECO Energy Co [Member] | Other deferred credits and other liabilities [Member]
Supplemental Balance Sheet Information [Line Items]
Other deferred credits and other liabilities	1	1
Baltimore Gas and Electric Company [Member]
Supplemental Balance Sheet Information [Line Items]
Other current liabilities	55	48
Other deferred credits and other liabilities	88	98
Operating Lease, Liability	4	19
Baltimore Gas and Electric Company [Member] | Other Noncurrent Assets [Member]
Supplemental Balance Sheet Information [Line Items]
Operating Lease, Right-of-Use Asset	2	16
Baltimore Gas and Electric Company [Member] | Other Current Liabilities [Member]
Supplemental Balance Sheet Information [Line Items]
Other current liabilities	0	15
Baltimore Gas and Electric Company [Member] | Other deferred credits and other liabilities [Member]
Supplemental Balance Sheet Information [Line Items]
Other deferred credits and other liabilities	4	4
Pepco Holdings LLC [Member]
Supplemental Balance Sheet Information [Line Items]
Other current liabilities	330	171
Other deferred credits and other liabilities	536	570
Operating Lease, Liability	198	226
Finance Lease, Liability, Current	12	10
Finance Lease, Liability, Noncurrent	64	64
Finance lease, liability	76	74
Pepco Holdings LLC [Member] | Other Noncurrent Assets [Member]
Supplemental Balance Sheet Information [Line Items]
Operating Lease, Right-of-Use Asset	180	209
Pepco Holdings LLC [Member] | Other Current Liabilities [Member]
Supplemental Balance Sheet Information [Line Items]
Other current liabilities	31	31
Pepco Holdings LLC [Member] | Other deferred credits and other liabilities [Member]
Supplemental Balance Sheet Information [Line Items]
Other deferred credits and other liabilities	167	195
Pepco Holdings LLC [Member] | Property, Plant and Equipment
Supplemental Balance Sheet Information [Line Items]
Finance Lease, Right-of-Use Asset, after Accumulated Amortization	74	73
Potomac Electric Power Company [Member]
Supplemental Balance Sheet Information [Line Items]
Other current liabilities	93	55
Other deferred credits and other liabilities	244	314
Operating Lease, Liability	40	46
Finance Lease, Liability, Current	4	3
Finance Lease, Liability, Noncurrent	21	23
Finance lease, liability	25	26
Potomac Electric Power Company [Member] | Other Noncurrent Assets [Member]
Supplemental Balance Sheet Information [Line Items]
Operating Lease, Right-of-Use Asset	36	43
Potomac Electric Power Company [Member] | Other Current Liabilities [Member]
Supplemental Balance Sheet Information [Line Items]
Other current liabilities	6	6
Potomac Electric Power Company [Member] | Other deferred credits and other liabilities [Member]
Supplemental Balance Sheet Information [Line Items]
Other deferred credits and other liabilities	34	40
Potomac Electric Power Company [Member] | Property, Plant and Equipment
Supplemental Balance Sheet Information [Line Items]
Finance Lease, Right-of-Use Asset, after Accumulated Amortization	25	25
Delmarva Power & Light Company [Member]
Supplemental Balance Sheet Information [Line Items]
Other current liabilities	136	59
Other deferred credits and other liabilities	84	89
Operating Lease, Liability	50	57
Finance Lease, Liability, Current	5	4
Finance Lease, Liability, Noncurrent	27	25
Finance lease, liability	32	29
Delmarva Power & Light Company [Member] | Other Noncurrent Assets [Member]
Supplemental Balance Sheet Information [Line Items]
Operating Lease, Right-of-Use Asset	39	46
Delmarva Power & Light Company [Member] | Other Current Liabilities [Member]
Supplemental Balance Sheet Information [Line Items]
Other current liabilities	8	8
Delmarva Power & Light Company [Member] | Other deferred credits and other liabilities [Member]
Supplemental Balance Sheet Information [Line Items]
Other deferred credits and other liabilities	42	49
Delmarva Power & Light Company [Member] | Property, Plant and Equipment
Supplemental Balance Sheet Information [Line Items]
Finance Lease, Right-of-Use Asset, after Accumulated Amortization	31	29
Atlantic City Electric Company [Member]
Supplemental Balance Sheet Information [Line Items]
Other current liabilities	58	12
Other deferred credits and other liabilities	100	49
Operating Lease, Liability	10	12
Finance Lease, Liability, Current	3	3
Finance Lease, Liability, Noncurrent	16	16
Finance lease, liability	19	19
Atlantic City Electric Company [Member] | Other Noncurrent Assets [Member]
Supplemental Balance Sheet Information [Line Items]
Operating Lease, Right-of-Use Asset	9	11
Atlantic City Electric Company [Member] | Other Current Liabilities [Member]
Supplemental Balance Sheet Information [Line Items]
Other current liabilities	3	3
Atlantic City Electric Company [Member] | Other deferred credits and other liabilities [Member]
Supplemental Balance Sheet Information [Line Items]
Other deferred credits and other liabilities	7	9
Atlantic City Electric Company [Member] | Property, Plant and Equipment
Supplemental Balance Sheet Information [Line Items]
Finance Lease, Right-of-Use Asset, after Accumulated Amortization	$ 18	$ 19