Accounts Receivable - Allowance for Credit Losses Rollforward (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Current period provision for expected credit losses			$ (86)	$ (130)
Commonwealth Edison Co
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Current period provision for expected credit losses			(4)	(40)
PECO Energy Co
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Current period provision for expected credit losses			(31)	(32)
Baltimore Gas and Electric Company
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Current period provision for expected credit losses			(4)	(18)
Pepco Holdings LLC
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Current period provision for expected credit losses			(47)	(42)
Potomac Electric Power Company
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Current period provision for expected credit losses			(27)	(21)
Delmarva Power and Light Company
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Current period provision for expected credit losses			(9)	(9)
Atlantic City Electric Company
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Current period provision for expected credit losses			(11)	(12)
Customer accounts receivable
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 323	$ 354	327	320
Current period provision for expected credit losses	72	38	144	141
Writeoffs, net of recoveries	54	51	130	120
Ending balance	341	341	341	341
Customer accounts receivable | Commonwealth Edison Co
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	67	81	59	73
Current period provision for expected credit losses	24	10	45	31
Writeoffs, net of recoveries	15	17	28	30
Ending balance	76	74	76	74
Customer accounts receivable | PECO Energy Co
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	101	107	105	105
Current period provision for expected credit losses	13	12	32	33
Writeoffs, net of recoveries	19	16	42	35
Ending balance	95	103	95	103
Customer accounts receivable | Baltimore Gas and Electric Company
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	50	57	54	38
Current period provision for expected credit losses	9	2	23	30
Writeoffs, net of recoveries	7	5	25	14
Ending balance	52	54	52	54
Customer accounts receivable | Pepco Holdings LLC
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	105	109	109	104
Current period provision for expected credit losses	26	14	44	47
Writeoffs, net of recoveries	13	12	35	40
Ending balance	118	111	118	111
Customer accounts receivable | Potomac Electric Power Company
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	50	42	47	37
Current period provision for expected credit losses	11	6	24	23
Writeoffs, net of recoveries	5	4	15	16
Ending balance	56	44	56	44
Customer accounts receivable | Delmarva Power and Light Company
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	21	22	21	18
Current period provision for expected credit losses	6	1	10	8
Writeoffs, net of recoveries	4	3	8	6
Ending balance	23	20	23	20
Customer accounts receivable | Atlantic City Electric Company
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	34	45	41	49
Current period provision for expected credit losses	9	7	10	16
Writeoffs, net of recoveries	4	5	12	18
Ending balance	39	47	39	47
Other receivables
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	87	81	82	72
Current period provision for expected credit losses	6	8	21	24
Writeoffs, net of recoveries	5	5	15	12
Ending balance	88	84	88	84
Other receivables | Commonwealth Edison Co
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	18	18	17	17
Current period provision for expected credit losses	3	2	6	5
Writeoffs, net of recoveries	1	2	3	4
Ending balance	20	18	20	18
Other receivables | PECO Energy Co
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	8	10	9	7
Current period provision for expected credit losses	2	2	3	6
Writeoffs, net of recoveries	2	1	4	2
Ending balance	8	11	8	11
Other receivables | Baltimore Gas and Electric Company
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	8	11	10	9
Current period provision for expected credit losses	3	2	5	6
Writeoffs, net of recoveries	2	1	6	3
Ending balance	9	12	9	12
Other receivables | Pepco Holdings LLC
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	53	42	46	39
Current period provision for expected credit losses	(2)	2	7	7
Writeoffs, net of recoveries	0	1	2	3
Ending balance	51	43	51	43
Other receivables | Potomac Electric Power Company
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	31	20	25	16
Current period provision for expected credit losses	(2)	2	4	6
Writeoffs, net of recoveries	0	0	0	0
Ending balance	29	22	29	22
Other receivables | Delmarva Power and Light Company
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	9	8	7	8
Current period provision for expected credit losses	0	(1)	2	(1)
Writeoffs, net of recoveries	0	0	0	0
Ending balance	9	7	9	7
Other receivables | Atlantic City Electric Company
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	13	14	14	15
Current period provision for expected credit losses	0	1	1	2
Writeoffs, net of recoveries	0	1	2	3
Ending balance	$ 13	$ 14	$ 13	$ 14