Accounts Receivable - Allowance for Credit Losses Rollforward (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Accounts Receivable, Allowance for Credit Loss [Line Items]
Current Period Provision for Expected Credit Losses	$ (173)	$ (160)	$ (150)
Commonwealth Edison Co [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Current Period Provision for Expected Credit Losses	(46)	(47)	(32)
PECO Energy Co [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Current Period Provision for Expected Credit Losses	(45)	(39)	(42)
Baltimore Gas and Electric Company [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Current Period Provision for Expected Credit Losses	(25)	(17)	(15)
Pepco Holdings LLC [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Current Period Provision for Expected Credit Losses	(58)	(24)	(43)
Potomac Electric Power Company [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Current Period Provision for Expected Credit Losses	(29)	(9)	(24)
Delmarva Power & Light Company [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Current Period Provision for Expected Credit Losses	(12)	(5)	(16)
Atlantic City Electric Company [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Current Period Provision for Expected Credit Losses	(16)	(10)	(2)
Customer accounts receivable
Accounts Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	320	334
Current Period Provision for Expected Credit Losses	176	96
Writeoffs, net of recoveries	169	110
Ending balance	327	320	334
Customer accounts receivable | Commonwealth Edison Co [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	73	97
Current Period Provision for Expected Credit Losses	29	21
Writeoffs, net of recoveries	43	45
Ending balance	59	73	97
Customer accounts receivable | PECO Energy Co [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	105	116
Current Period Provision for Expected Credit Losses	52	23
Writeoffs, net of recoveries	52	34
Ending balance	105	105	116
Customer accounts receivable | Baltimore Gas and Electric Company [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	38	35
Current Period Provision for Expected Credit Losses	37	15
Writeoffs, net of recoveries	21	12
Ending balance	54	38	35
Customer accounts receivable | Pepco Holdings LLC [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	104	86
Current Period Provision for Expected Credit Losses	58	37
Writeoffs, net of recoveries	53	19
Ending balance	109	104	86
Customer accounts receivable | Potomac Electric Power Company [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	37	32
Current Period Provision for Expected Credit Losses	31	13
Writeoffs, net of recoveries	21	8
Ending balance	47	37	32
Customer accounts receivable | Delmarva Power & Light Company [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	18	22
Current Period Provision for Expected Credit Losses	12	6
Writeoffs, net of recoveries	9	10
Ending balance	21	18	22
Customer accounts receivable | Atlantic City Electric Company [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	49	32
Current Period Provision for Expected Credit Losses	15	18
Writeoffs, net of recoveries	23	1
Ending balance	41	49	32
Other Receivables
Accounts Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	72	71
Current Period Provision for Expected Credit Losses	26	11
Writeoffs, net of recoveries	16	10
Ending balance	82	72	71
Other Receivables | Commonwealth Edison Co [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	17	21
Current Period Provision for Expected Credit Losses	3	(2)
Writeoffs, net of recoveries	3	2
Ending balance	17	17	21
Other Receivables | PECO Energy Co [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	7	8
Current Period Provision for Expected Credit Losses	6	3
Writeoffs, net of recoveries	4	4
Ending balance	9	7	8
Other Receivables | Baltimore Gas and Electric Company [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	9	9
Current Period Provision for Expected Credit Losses	6	4
Writeoffs, net of recoveries	5	4
Ending balance	10	9	9
Other Receivables | Pepco Holdings LLC [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	39	33
Current Period Provision for Expected Credit Losses	11	6
Writeoffs, net of recoveries	4	0
Ending balance	46	39	33
Other Receivables | Potomac Electric Power Company [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	16	13
Current Period Provision for Expected Credit Losses	9	3
Writeoffs, net of recoveries	0	0
Ending balance	25	16	13
Other Receivables | Delmarva Power & Light Company [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	8	9
Current Period Provision for Expected Credit Losses	(1)	(1)
Writeoffs, net of recoveries	0	0
Ending balance	7	8	9
Other Receivables | Atlantic City Electric Company [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	15	11
Current Period Provision for Expected Credit Losses	3	4
Writeoffs, net of recoveries	4	0
Ending balance	$ 14	$ 15	$ 11