Schedule II - Valuation and Qualifying Accounts Schedule (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
SEC Schedule, 12-09, Allowance, Credit Loss
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 409	$ 392	$ 405
Charged to Costs and Expenses	171	174	107
Charged to Other Accounts	20	28	0
Deductions	201	185	120
Balance at End of Period	399	409	392
Deferred Tax Valuation Allowance
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	94	37	4
Charged to Costs and Expenses	0	0	0
Charged to Other Accounts	20	57	33
Deductions	0	0	0
Balance at End of Period	114	94	37
SEC Schedule, 12-09, Allowance, Notes Receivable
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	7	14
Balance at End of Period	6	7	14
Commonwealth Edison Co | SEC Schedule, 12-09, Allowance, Credit Loss
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	76	90	118
Charged to Costs and Expenses	45	24	18
Charged to Other Accounts	13	8	1
Deductions	48	46	47
Balance at End of Period	86	76	90
PECO Energy Co | SEC Schedule, 12-09, Allowance, Credit Loss
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	114	112	124
Charged to Costs and Expenses	43	44	32
Charged to Other Accounts	9	14	(6)
Deductions	63	56	38
Balance at End of Period	103	114	112
PECO Energy Co | Deferred Tax Valuation Allowance
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	7	3	1
Charged to Costs and Expenses	0	0	0
Charged to Other Accounts	0	4	2
Deductions	0	0	0
Balance at End of Period	7	7	3
PECO Energy Co | SEC Schedule, 12-09, Allowance, Notes Receivable
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	7	14
Balance at End of Period	6	7	14
Baltimore Gas and Electric Company | SEC Schedule, 12-09, Allowance, Credit Loss
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	64	47	44
Charged to Costs and Expenses	26	37	16
Charged to Other Accounts	5	6	3
Deductions	42	26	16
Balance at End of Period	53	64	47
Baltimore Gas and Electric Company | Deferred Tax Valuation Allowance
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	3	0	0
Charged to Costs and Expenses	0	0	0
Charged to Other Accounts	0	3	0
Deductions	0	0	0
Balance at End of Period	3	3	0
Pepco Holdings LLC | SEC Schedule, 12-09, Allowance, Credit Loss
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	155	143	119
Charged to Costs and Expenses	57	69	41
Charged to Other Accounts	(7)	0	2
Deductions	48	57	19
Balance at End of Period	157	155	143
Pepco Holdings LLC | Deferred Tax Valuation Allowance
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	35	31	0
Charged to Costs and Expenses	0	0	0
Charged to Other Accounts	0	4	31
Deductions	0	0	0
Balance at End of Period	35	35	31
Potomac Electric Power Company | SEC Schedule, 12-09, Allowance, Credit Loss
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	72	53	45
Charged to Costs and Expenses	31	36	14
Charged to Other Accounts	(5)	4	2
Deductions	18	21	8
Balance at End of Period	80	72	53
Delmarva Power & Light Company | SEC Schedule, 12-09, Allowance, Credit Loss
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	28	26	31
Charged to Costs and Expenses	10	13	6
Charged to Other Accounts	0	(2)	(1)
Deductions	11	9	10
Balance at End of Period	27	28	26
Delmarva Power & Light Company | Deferred Tax Valuation Allowance
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	32	31	0
Charged to Costs and Expenses	0	0	0
Charged to Other Accounts	0	1	31
Deductions	0	0	0
Balance at End of Period	32	32	31
Atlantic City Electric Company | SEC Schedule, 12-09, Allowance, Credit Loss
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	55	64	43
Charged to Costs and Expenses	16	20	21
Charged to Other Accounts	(2)	(2)	1
Deductions	19	27	1
Balance at End of Period	$ 50	$ 55	$ 64