Discontinued Operations and Disposal Groups (Details) - Income Statement - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Discontinued Operations - Income Statement
Operating and maintenance	$ 1,151	$ 1,178
Cost, Depreciation and Amortization	860	817
Taxes, Miscellaneous	355	354
Costs and Expenses	4,457	4,427
Other, net	109	137
Nonoperating Income (Expense)	(303)	(201)
Income taxes	134	218
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	0	117
Net income (loss) attributable to noncontrolling interests	0	1
Net Income (Loss) from Discontinued Operations Available to Common Shareholders, Basic	0	116
Total transaction and transition costs incurred related to the Separation		52
Exelon Generation Co L L C [Member]
Discontinued Operations - Income Statement
Revenue from Contract with Customer, Including Assessed Tax	0	1,855
Revenue from Related Parties	0	161
Disposal Group, Including Discontinued Operation, Revenue	0	2,016
Purchased power and/or fuel	0	1,138
Operating and maintenance	0	371
Cost, Depreciation and Amortization	0	94
Taxes, Miscellaneous	0	44
Costs and Expenses	0	1,647
Gain (Loss) on Disposition of Assets	0	10
Disposal Group, Including Discontinued Operation, Operating Income (Loss)	0	379
Disposal Group, Including Discontinued Operation, Interest Expense	0	(20)
Other, net	0	(281)
Nonoperating Income (Expense)	0	(301)
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax	0	78
Income taxes	0	(40)
Income (Loss) from Equity Method Investments	0	(1)
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	0	117
Net income (loss) attributable to noncontrolling interests	0	1
Net Income (Loss) from Discontinued Operations Available to Common Shareholders, Basic	$ 0	$ 116