Lessee - Components of Lease Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Schedule of Components of Lease Cost [Line Items]
Operating Lease, Cost	$ 66	$ 84	$ 98
Variable Lease, Cost	8	7	7
Total Lease Cost	74	91	105
Sublease Income	4	4	4
Commonwealth Edison Co [Member]
Schedule of Components of Lease Cost [Line Items]
Operating Lease, Cost	2	3	3
Variable Lease, Cost	1	1	1
Total Lease Cost	3	4	4
PECO Energy Co [Member]
Schedule of Components of Lease Cost [Line Items]
Operating Lease, Cost	0	0	1
Variable Lease, Cost	0	0	0
Total Lease Cost	0	0	1
Baltimore Gas and Electric Company [Member]
Schedule of Components of Lease Cost [Line Items]
Operating Lease, Cost	15	30	33
Variable Lease, Cost	0	1	1
Total Lease Cost	15	31	34
Pepco Holdings LLC [Member]
Schedule of Components of Lease Cost [Line Items]
Operating Lease, Cost	42	43	46
Variable Lease, Cost	2	1	2
Total Lease Cost	44	44	48
Finance Lease, Right-of-Use Asset, Amortization	14	11	7
Finance Lease, Interest Expense	4	2	2
Finance Lease, Cost	18	13	9
Potomac Electric Power Company [Member]
Schedule of Components of Lease Cost [Line Items]
Operating Lease, Cost	10	10	11
Variable Lease, Cost	1	0	1
Total Lease Cost	11	10	12
Finance Lease, Right-of-Use Asset, Amortization	5	4	3
Finance Lease, Interest Expense	1	1	0
Finance Lease, Cost	6	5	3
Delmarva Power & Light Company [Member]
Schedule of Components of Lease Cost [Line Items]
Operating Lease, Cost	12	12	13
Variable Lease, Cost	1	0	1
Total Lease Cost	13	12	14
Finance Lease, Right-of-Use Asset, Amortization	6	4	3
Finance Lease, Interest Expense	2	1	1
Finance Lease, Cost	8	5	4
Atlantic City Electric Company [Member]
Schedule of Components of Lease Cost [Line Items]
Operating Lease, Cost	6	6	6
Variable Lease, Cost	1	0	0
Total Lease Cost	7	6	6
Finance Lease, Right-of-Use Asset, Amortization	3	3	2
Finance Lease, Interest Expense	1	0	0
Finance Lease, Cost	$ 4	$ 3	$ 2