Discontinued Operations and Disposal Groups (Details) - Income Statement - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Discontinued Operations - Income Statement
Operating and maintenance	$ 1,109	$ 1,073	$ 2,288	$ 2,155
Cost, Depreciation and Amortization	830	736	1,647	1,494
Taxes, Miscellaneous	330	314	684	631
Costs and Expenses	3,543	3,444	7,971	7,252
Other, net	175	73	313	131
Nonoperating Income (Expense)	(183)	(251)	(384)	(512)
Income taxes	46	3	263	42
Income (Loss) from Equity Method Investments	0	0	0	1
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	0	150	117	(640)
Net income (loss) attributable to noncontrolling interests	0	75	1	99
Net Income (Loss) from Discontinued Operations Available to Common Shareholders, Basic	$ 0	75	116	(739)
Total transaction and transition costs incurred related to the Separation		4	52	7
Total transaction costs relating to the Separation			19
Exelon Generation Co L L C [Member]
Discontinued Operations - Income Statement
Revenue from Contract with Customer, Including Assessed Tax		3,900	1,855	9,165
Revenue from Related Parties		255	161	549
Disposal Group, Including Discontinued Operation, Revenue		4,155	2,016	9,714
Purchased power and/or fuel		1,947	1,138	6,557
Operating and maintenance		1,382	371	2,287
Cost, Depreciation and Amortization		930	94	1,869
Taxes, Miscellaneous		118	44	239
Costs and Expenses		4,377	1,647	10,952
Gain (Loss) on Disposition of Assets		8	10	79
Disposal Group, Including Discontinued Operation, Operating Income (Loss)		(214)	379	(1,159)
Disposal Group, Including Discontinued Operation, Interest Expense		(72)	(20)	(140)
Other, net		508	(281)	675
Nonoperating Income (Expense)		436	(301)	535
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax		222	78	(624)
Income taxes		71	(40)	13
Income (Loss) from Equity Method Investments		(1)	(1)	(3)
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest		150	117	(640)
Net income (loss) attributable to noncontrolling interests		75	1	99
Net Income (Loss) from Discontinued Operations Available to Common Shareholders, Basic		$ 75	$ 116	$ (739)