Discontinued Operations and Disposal Groups (Details) - Narrative - USD ($) $ in Millions	3 Months Ended		8 Months Ended	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Feb. 01, 2022
Discontinued Operations - Income Statement
Discontinued Operation, Intra-Entity Amounts, Discontinued Operation after Disposal, Expense	$ 33	$ 68	$ 193	$ 127
Operating and maintenance	1,187	1,148		3,535	$ 3,436
Total other income and (deductions)	(356)	(243)		(946)	(628)
Net income from discontinued operations	0	0		0	116
Income taxes	67	92		274	356
Other, net	81	122		331	435
Net income attributable to noncontrolling interests	0	0		0	1
Taxes, Miscellaneous	383	377		1,063	1,061
Total operating revenues	5,980	4,845		16,360	14,412
Cost, Depreciation and Amortization	890	825		2,616	2,472
Total operating expenses	4,857	3,834		13,429	11,804
Net income from discontinued operations after income taxes (Note 2)	0	0		0	117
Total liabilities	73,789			73,789		$ 70,605
Total assets	99,259			99,259		95,349
Decrease in capital expenditures not paid				(169)	(147)
Collection of deferred purchase price				0	169
Other non-cash operating activities				237	(265)
Unrealized Gain (Loss) on Derivatives				(21)	59
Capital expenditures				5,540	5,179
Depreciation and amortization				2,616	2,679
Gain (Loss) on Investments				0	(205)
Deferred income taxes and amortization of investment tax credits				210	256
Increase in DPP				0	348
Gain (Loss) on Sale of Assets and Asset Impairment Charges				0	8
Net unrealized losses on equity investments				0	(16)
Exelon Generation Co L L C
Discontinued Operations - Income Statement
Discontinued Operation, Intra-Entity Amounts, Discontinued Operation after Disposal, Expense	4	12	$ 32	13
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax	0	0		0	78
Electric operating revenues	0	0		0	1,855
Purchased power and/or fuel	0	0		0	1,138
Gain (Loss) on Disposition of Assets	0	0		0	10
Disposal Group, Including Discontinued Operation, Interest Expense	0	0		0	20
Operating and maintenance	0	0		0	371
Total other income and (deductions)	0	0		0	(301)
Net income from discontinued operations	0	0		0	116
Income taxes	0	0		0	(40)
Other, net	0	0		0	(281)
Net income attributable to noncontrolling interests	0	0		0	1
Taxes, Miscellaneous	0	0		0	44
Income (Loss) from Equity Method Investments	0	0		0	(1)
Cost, Depreciation and Amortization	0	0		0	94
Disposal Group, Including Discontinued Operation, Operating Income (Loss)	0	0		0	379
Total operating expenses	0	0		0	1,647
Net income from discontinued operations after income taxes (Note 2)	0	0		0	117
Disposal Group, Including Discontinued Operation, Revenue	0	0		0	2,016
Total liabilities	0			0		0
Total assets	0			0		$ 0
Net assets							$ (11,573)
Decrease in capital expenditures not paid				0	(128)
Collection of deferred purchase price				0	169
Other non-cash operating activities				0	36
Increase in PPE related to ARO update				0	335
Unrealized Gain (Loss) on Derivatives				0	59
Capital expenditures				0	227
Depreciation and amortization				0	207
Gain (Loss) on Investments				0	(205)
Deferred income taxes and amortization of investment tax credits				0	(143)
Increase in DPP				0	348
Gain (Loss) on Sale of Assets and Asset Impairment Charges				0	(9)
Net unrealized losses on equity investments				0	(16)
Exelon Generation Co L L C | Related Party
Discontinued Operations - Income Statement
Operating revenues from affiliates	$ 0	$ 0		$ 0	$ 161