Discontinued Operations and Disposal Groups - Narrative (Details) - USD ($) $ in Millions		11 Months Ended	12 Months Ended
	Jan. 31, 2022	Dec. 31, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Sep. 30, 2022	Feb. 01, 2022
Business Dispositions [Line Items]
Separation Cash Payment			$ 9
Discontinued Operation, Intra-Entity Amounts, Discontinued Operation after Disposal, Expense		$ 266	151
Total assets		95,349	101,546	$ 95,349
Total liabilities		70,605	75,791	70,605
Net income (loss) attributable to noncontrolling interests			0	1	$ 123
Income taxes			374	349	38
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest			0	117	213
Operating and maintenance			4,559	4,673	4,547
Total other income and (deductions)			(1,321)	(912)	(1,028)
Other Nonoperating Income (Expense)			408	535	261
Depreciation and amortization			3,506	3,325	3,033
Net Income (Loss) from Discontinued Operations Available to Common Shareholders, Basic			0	116	90
Total operating expenses			17,714	15,761	15,256
Taxes, Miscellaneous			1,408	1,390	1,291
(Decrease) increase in PP&E related to ARO update			(13)	332	642
Deferred Income Taxes and Tax Credits			319	255	18
Other non-cash operating activities			335	(370)	200
Gain (Loss) on Investments			0	(205)	586
Increase in DPP			0	348	3,652
Collection of DPP			0	169	3,902
Net fair value changes related to derivatives			(22)	53	568
Capital expenditures			7,408	7,147	7,981
(Decrease) increase in capital expenditures not paid			(215)	36	16
Gain (Loss) on Sale of Assets and Asset Impairment Charges			10	8	201
Net unrealized losses (gains) on equity investments			0	(16)	(160)
Depreciation, Amortization and Accretion, Net			3,506	3,533	7,573
Exelon Generation Co L L C
Business Dispositions [Line Items]
Proceeds from sale and collection of notes receivable				258
Exelon Generation Co L L C
Business Dispositions [Line Items]
Discontinued Operation, Intra-Entity Amounts, Discontinued Operation after Disposal, Expense		43	14
Total assets		0	0	0
Total liabilities		0	0	0
Net Assets							$ (11,573)
Net income (loss) attributable to noncontrolling interests			0	1	123
Operating revenues			0	1,855	18,466
Income taxes			0	(40)	332
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax			0	78	554
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
Operating and maintenance			0	371	4,174
Disposal Group, Including Discontinued Operation, Revenue			0	2,016	19,655
Gain (Loss) on Disposition of Assets			0	10	201
Total other income and (deductions)			0	(301)	513
Purchased power and/or fuel			0	1,138	12,163
Other Nonoperating Income (Expense)			0	(281)	795
Depreciation and amortization			0	94	3,003
Disposal Group, Including Discontinued Operation, Interest Expense			0	20	282
Net Income (Loss) from Discontinued Operations Available to Common Shareholders, Basic			0	116	90
Total operating expenses			0	1,647	19,815
Disposal Group, Including Discontinued Operation, Operating Income (Loss)			0	379	41
Operating revenues from affiliates				161	1,189
Taxes, Miscellaneous			0	44	475
(Decrease) increase in PP&E related to ARO update			0	335	618
Deferred Income Taxes and Tax Credits			0	(143)	(224)
Other non-cash operating activities			0	36	(946)
Gain (Loss) on Investments			0	205	(586)
Increase in DPP			0	348	3,652
Collection of DPP			0	169	3,902
Net fair value changes related to derivatives			0	(59)	(568)
Capital expenditures			0	227	1,341
(Decrease) increase in capital expenditures not paid			0	(128)	96
Gain (Loss) on Sale of Assets and Asset Impairment Charges			0	9	(201)
Net unrealized losses (gains) on equity investments			0	16	160
Depreciation, Amortization and Accretion, Net			0	207	4,540
Exelon Generation Co L L C | Related Party
Business Dispositions [Line Items]
Operating revenues from affiliates			0
Corporate, Non-Segment
Business Dispositions [Line Items]
Common Stock, Shares, Issued							326,663,937
Separation Cash Payment	$ 1,750
Total assets		40,578	43,632	40,578
Total liabilities		15,834	17,877	15,834
Income taxes			(212)	(21)	(48)
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest			0	116	90
Total other income and (deductions)			2,212	2,064	1,575
Other Nonoperating Income (Expense)			19	22	0
Total operating expenses			96	31	$ 7
Corporate, Non-Segment | Notes Payable to Banks
Business Dispositions [Line Items]
Debt instrument, face amount			$ 2,500
Corporate, Non-Segment | ShortTermDebtSOFRplus075Jan2023
Business Dispositions [Line Items]
Short-term loans		1,150		1,150		$ 1,150
Corporate, Non-Segment | SMBCTermLoanJuly2023 | Notes Payable to Banks
Business Dispositions [Line Items]
Debt instrument, face amount		300		300
Corporate, Non-Segment | USBTermLoanJuly2023 | Notes Payable to Banks
Business Dispositions [Line Items]
Debt instrument, face amount		300		300
Corporate, Non-Segment | PNCTermLoanJuly2023 | Notes Payable to Banks
Business Dispositions [Line Items]
Debt instrument, face amount		$ 250		$ 250