Related Party Transactions - Operating Revenues and Purchased Power and Fuel From Affiliates (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Related Party Transaction [Line Items]
Total operating revenues from affiliates	$ 160	$ 1,188	$ 1,211
ComEd
Related Party Transaction [Line Items]
Total operating revenues from affiliates	58	376	330
PECO
Related Party Transaction [Line Items]
Total operating revenues from affiliates	33	196	190
BGE
Related Party Transaction [Line Items]
Total operating revenues from affiliates	18	236	315
PHI
Related Party Transaction [Line Items]
Total operating revenues from affiliates	51	366	367
Pepco
Related Party Transaction [Line Items]
Total operating revenues from affiliates	39	270	279
DPL
Related Party Transaction [Line Items]
Total operating revenues from affiliates	10	79	75
ACE
Related Party Transaction [Line Items]
Total operating revenues from affiliates	2	17	13
Other
Related Party Transaction [Line Items]
Total operating revenues from affiliates	$ 0	$ 14	$ 9