Accounts Receivable - Allowance for Credit Losses Rollforward (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current period provision for expected credit losses			$ (46)	$ (96)
Commonwealth Edison Co [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current period provision for expected credit losses			(1)	(29)
PECO Energy Co [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current period provision for expected credit losses			(19)	(21)
Baltimore Gas and Electric Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current period provision for expected credit losses			(4)	(18)
Pepco Holdings LLC [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current period provision for expected credit losses			(22)	(29)
Potomac Electric Power Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current period provision for expected credit losses			(13)	(16)
Delmarva Power and Light Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current period provision for expected credit losses			(3)	(6)
Atlantic City Electric Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current period provision for expected credit losses			(6)	(7)
Customer accounts receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	$ 389	$ 389	327	320
Current period provision for expected credit losses	(35)	(9)	71	101
Writeoffs, net of recoveries	31	26	75	67
Ending balance	323	354	323	354
Customer accounts receivable | Commonwealth Edison Co [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	74	92	59	73
Current period provision for expected credit losses	(1)	(5)	21	21
Writeoffs, net of recoveries	6	6	13	13
Ending balance	67	81	67	81
Customer accounts receivable | PECO Energy Co [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	130	125	105	105
Current period provision for expected credit losses	(20)	(10)	18	21
Writeoffs, net of recoveries	9	8	22	19
Ending balance	101	107	101	107
Customer accounts receivable | Baltimore Gas and Electric Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	73	59	54	38
Current period provision for expected credit losses	(16)	2	14	28
Writeoffs, net of recoveries	7	4	18	9
Ending balance	50	57	50	57
Customer accounts receivable | Pepco Holdings LLC [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	112	113	109	104
Current period provision for expected credit losses	2	4	18	31
Writeoffs, net of recoveries	9	8	22	26
Ending balance	105	109	105	109
Customer accounts receivable | Potomac Electric Power Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	49	40	47	37
Current period provision for expected credit losses	4	5	13	16
Writeoffs, net of recoveries	3	3	10	11
Ending balance	50	42	50	42
Customer accounts receivable | Delmarva Power and Light Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	26	24	21	18
Current period provision for expected credit losses	(3)	0	4	7
Writeoffs, net of recoveries	2	2	4	3
Ending balance	21	22	21	22
Customer accounts receivable | Atlantic City Electric Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	37	49	41	49
Current period provision for expected credit losses	1	(1)	1	8
Writeoffs, net of recoveries	4	3	8	12
Ending balance	34	45	34	45
Other receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	91	81	82	72
Current period provision for expected credit losses	1	2	15	15
Writeoffs, net of recoveries	5	2	10	6
Ending balance	87	81	87	81
Other receivables | Commonwealth Edison Co [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	18	20	17	17
Current period provision for expected credit losses	1	(2)	3	2
Writeoffs, net of recoveries	1	0	2	1
Ending balance	18	18	18	18
Other receivables | PECO Energy Co [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	11	9	9	7
Current period provision for expected credit losses	(2)	2	1	4
Writeoffs, net of recoveries	1	1	2	1
Ending balance	8	10	8	10
Other receivables | Baltimore Gas and Electric Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	12	11	10	9
Current period provision for expected credit losses	(2)	1	2	4
Writeoffs, net of recoveries	2	1	4	2
Ending balance	8	11	8	11
Other receivables | Pepco Holdings LLC [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	50	41	46	39
Current period provision for expected credit losses	4	1	9	5
Writeoffs, net of recoveries	1	0	2	2
Ending balance	53	42	53	42
Other receivables | Potomac Electric Power Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	28	18	25	16
Current period provision for expected credit losses	3	2	6	4
Writeoffs, net of recoveries	0	0	0	0
Ending balance	31	20	31	20
Other receivables | Delmarva Power and Light Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	8	9	7	8
Current period provision for expected credit losses	1	(1)	2	0
Writeoffs, net of recoveries	0	0	0	0
Ending balance	9	8	9	8
Other receivables | Atlantic City Electric Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	14	14	14	15
Current period provision for expected credit losses	0	0	1	1
Writeoffs, net of recoveries	1	0	2	2
Ending balance	$ 13	$ 14	$ 13	$ 14