Accounts Receivable - Allowance for Credit Losses Rollforward (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Current period provision for expected credit losses	$ (63)	$ (70)
Commonwealth Edison Co
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Current period provision for expected credit losses	(2)	0
PECO Energy Co
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Current period provision for expected credit losses	(27)	(37)
Baltimore Gas and Electric Company
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Current period provision for expected credit losses	(12)	(18)
Pepco Holdings LLC
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Current period provision for expected credit losses	(22)	(15)
Potomac Electric Power Company
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Current period provision for expected credit losses	(16)	(7)
Delmarva Power and Light Company
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Current period provision for expected credit losses	(3)	(5)
Atlantic City Electric Company
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Current period provision for expected credit losses	(3)	(3)
Customer accounts receivable
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	317	327
Current period provision for expected credit losses	79	108
Writeoffs, net of recoveries	50	46
Ending balance	346	389
Customer accounts receivable | Commonwealth Edison Co
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	69	59
Current period provision for expected credit losses	22	22
Writeoffs, net of recoveries	9	7
Ending balance	82	74
Customer accounts receivable | PECO Energy Co
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	95	105
Current period provision for expected credit losses	23	39
Writeoffs, net of recoveries	11	14
Ending balance	107	130
Customer accounts receivable | Baltimore Gas and Electric Company
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	46	54
Current period provision for expected credit losses	15	30
Writeoffs, net of recoveries	9	11
Ending balance	52	73
Customer accounts receivable | Pepco Holdings LLC
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	107	109
Current period provision for expected credit losses	19	17
Writeoffs, net of recoveries	21	14
Ending balance	105	112
Customer accounts receivable | Potomac Electric Power Company
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	52	47
Current period provision for expected credit losses	12	9
Writeoffs, net of recoveries	12	7
Ending balance	52	49
Customer accounts receivable | Delmarva Power and Light Company
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	19	21
Current period provision for expected credit losses	3	7
Writeoffs, net of recoveries	5	2
Ending balance	17	26
Customer accounts receivable | Atlantic City Electric Company
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	36	41
Current period provision for expected credit losses	4	1
Writeoffs, net of recoveries	4	5
Ending balance	36	37
Other receivables
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	82	82
Current period provision for expected credit losses	18	14
Writeoffs, net of recoveries	4	5
Ending balance	96	91
Other receivables | Commonwealth Edison Co
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	17	17
Current period provision for expected credit losses	3	2
Writeoffs, net of recoveries	1	1
Ending balance	19	18
Other receivables | PECO Energy Co
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	8	9
Current period provision for expected credit losses	5	3
Writeoffs, net of recoveries	0	1
Ending balance	13	11
Other receivables | Baltimore Gas and Electric Company
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	7	10
Current period provision for expected credit losses	2	4
Writeoffs, net of recoveries	2	2
Ending balance	7	12
Other receivables | Pepco Holdings LLC
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	50	46
Current period provision for expected credit losses	8	5
Writeoffs, net of recoveries	1	1
Ending balance	57	50
Other receivables | Potomac Electric Power Company
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	28	25
Current period provision for expected credit losses	7	3
Writeoffs, net of recoveries	0	0
Ending balance	35	28
Other receivables | Delmarva Power and Light Company
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	8	7
Current period provision for expected credit losses	0	1
Writeoffs, net of recoveries	0	0
Ending balance	8	8
Other receivables | Atlantic City Electric Company
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	14	14
Current period provision for expected credit losses	1	1
Writeoffs, net of recoveries	1	1
Ending balance	$ 14	$ 14