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, 2022			$ 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			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			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			14,198	1,588	10,316	2,294
Beginning Balance at Dec. 31, 2023	25,755		14,363	1,588	10,401	2,374
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	658	658	193			193
Common stock dividends	(381)	(381)	(194)			(194)
Contributions from parent			39		39
Ending Balance at Mar. 31, 2024			14,401	1,588	10,440	2,373
Beginning Balance at Dec. 31, 2023	25,755		14,363	1,588	10,401	2,374
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,813		823
Ending Balance at Sep. 30, 2024	26,622		14,721	1,588	10,518	2,615
Beginning Balance at Mar. 31, 2024			14,401	1,588	10,440	2,373
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	448	448	270			270
Common stock dividends	(380)	(380)	(194)			(194)
Contributions from parent			39		39
Ending Balance at Jun. 30, 2024			14,516	1,588	10,479	2,449
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	707	707	360			360
Common stock dividends	(381)	$ (381)	(194)			(194)
Contributions from parent			39		39
Ending Balance at Sep. 30, 2024	$ 26,622		$ 14,721	$ 1,588	$ 10,518	$ 2,615