Discontinued Operations Income Statement - (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Business Dispositions [Line Items]
Operating and maintenance	$ 4,559	$ 4,673	$ 4,547
Depreciation and amortization	3,506	3,325	3,033
Taxes, Miscellaneous	1,408	1,390	1,291
Total operating expenses	17,714	15,761	15,256
Other Nonoperating Income (Expense)	408	535	261
Total other income and (deductions)	(1,321)	(912)	(1,028)
Income taxes	374	349	38
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	0	117	213
Net income (loss) attributable to noncontrolling interests	0	1	123
Net Income (Loss) from Discontinued Operations Available to Common Shareholders, Basic	0	116	90
Total transaction and transition costs incurred related to the Separation		52	43
Exelon Generation Co L L C
Business Dispositions [Line Items]
Operating revenues	0	1,855	18,466
Operating revenues from affiliates		161	1,189
Disposal Group, Including Discontinued Operation, Revenue	0	2,016	19,655
Purchased power and/or fuel	0	1,138	12,163
Operating and maintenance	0	371	4,174
Depreciation and amortization	0	94	3,003
Taxes, Miscellaneous	0	44	475
Total operating expenses	0	1,647	19,815
Gain (Loss) on Disposition of Assets	0	10	201
Disposal Group, Including Discontinued Operation, Operating Income (Loss)	0	379	41
Disposal Group, Including Discontinued Operation, Interest Expense	0	(20)	(282)
Other Nonoperating Income (Expense)	0	(281)	795
Total other income and (deductions)	0	(301)	513
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax	0	78	554
Income taxes	0	(40)	332
Equity in losses of unconsolidated affiliates	0	(1)	(9)
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	0	117	213
Net income (loss) attributable to noncontrolling interests	0	1	123
Net Income (Loss) from Discontinued Operations Available to Common Shareholders, Basic	$ 0	$ 116	$ 90