Consolidated Statements of Changes in Shareholders Equity (Unaudited) - ComEd - USD ($) $ in Millions	Total	Retained Earnings	Commonwealth Edison Co	Commonwealth Edison Co Common Stock	Commonwealth Edison Co Other Paid-in-Capital [Member]	Commonwealth Edison Co Retained Earnings
Beginning Balance at Dec. 31, 2021			$ 12,355	$ 1,588	$ 9,076	$ 1,691
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 598	$ 597	188			188
Common stock dividends	(332)	(332)	(144)			(144)
Contributions from parent			167		167
Ending Balance at Mar. 31, 2022			12,566	1,588	9,243	1,735
Beginning Balance at Dec. 31, 2021			12,355	1,588	9,076	1,691
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,739		706
Ending Balance at Sep. 30, 2022			13,130	1,588	9,579	1,963
Beginning Balance at Mar. 31, 2022			12,566	1,588	9,243	1,735
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	465	465	227			227
Common stock dividends	(332)	(332)	(145)			(145)
Contributions from parent			168		168
Ending Balance at Jun. 30, 2022			12,816	1,588	9,411	1,817
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	676	676	291			291
Common stock dividends	(335)	(335)	(145)			(145)
Contributions from parent			168		168
Ending Balance at Sep. 30, 2022			13,130	1,588	9,579	1,963
Beginning Balance at Dec. 31, 2022	24,744		13,364	1,588	9,746	2,030
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	669	669	241			241
Common stock dividends	(359)	(359)	(187)			(187)
Contributions from parent			186		186
Ending Balance at Mar. 31, 2023			13,604	1,588	9,932	2,084
Beginning Balance at Dec. 31, 2022	24,744		13,364	1,588	9,746	2,030
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,711		822
Ending Balance at Sep. 30, 2023	25,470		14,198	1,588	10,316	2,294
Beginning Balance at Mar. 31, 2023			13,604	1,588	9,932	2,084
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	343	343	249			249
Common stock dividends	(359)	(359)	(187)			(187)
Contributions from parent			186		186
Ending Balance at Jun. 30, 2023			13,852	1,588	10,118	2,146
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	700	700	333			333
Common stock dividends	(358)	$ (358)	(185)			(185)
Contributions from parent			198		198
Ending Balance at Sep. 30, 2023	$ 25,470		$ 14,198	$ 1,588	$ 10,316	$ 2,294