Discontinued Operations (Details) - Balance Sheet - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Business Dispositions [Line Items]
Restricted cash	$ 566	$ 321	$ 349	$ 358
Customer accounts receivable	2,544	2,189
Customer allowance for credit losses	327	320
Other accounts receivable	1,426	1,068
Other allowance for credit losses	(82)	(72)
Other accounts receivable, net	1,344	996
Fossil fuel and emission allowances	208	105
Materials and supplies	547	476
Currents assets of discontinued operations	0	7,835
Accumulated depreciation and amortization	15,930	14,430
Investments	232	250
Other	1,141	885
Property, plant, and equipment, deferred debits, and other assets of discontinued operations	0	38,509
Total assets	95,349	133,013
Short-term Debt	2,586	1,248
Long-term Debt and Lease Obligation, Current	1,802	2,153
Mark-to-market derivative liabilities, current	8	18
Current liabilities of discontinued operations	0	7,940
Long-term Debt, Excluding Current Maturities	35,272	30,749
Deferred income taxes and unamortized investment tax credits	11,250	10,611
Asset retirement obligations, noncurrent	269	271
Derivative Liability, Noncurrent	83	201
Other deferred credits and other liabilities	1,967	1,573
Long-term debt, deferred credits, and other liabilities of discontinued operations	0	25,676
Total liabilities	$ 70,605	98,218
Exelon Generation Co L L C [Member]
Business Dispositions [Line Items]
Disposal Group, Including Discontinued Operation, Cash and Cash Equivalents		510
Restricted cash		72
Customer accounts receivable		1,724
Customer allowance for credit losses		(55)
Disposal Group, Including Discontinued Operation, Accounts, Notes and Loans Receivable, Net		1,669
Other accounts receivable		596
Other allowance for credit losses		(4)
Other accounts receivable, net		592
Mark-to-market derivative assets, current		2,169
Fossil fuel and emission allowances		284
Materials and supplies		1,004
Renewable energy credits, current		529
Disposal Group, Including Discontinued Operations, Assets, Current - Assets held for sale		13
Disposal Group, Including Discontinued Operation, Other Assets, Current		993
Currents assets of discontinued operations		7,835
Disposal Group, Including Discontinued Operation, Property, Plant and Equipment, Noncurrent		19,661
Accumulated depreciation and amortization		15,888
Decommissioning Fund Investments		15,938
Investments		193
Mark-to-market derivative assets, noncurrent		949
Other		1,768
Property, plant, and equipment, deferred debits, and other assets of discontinued operations		38,509
Total assets		46,344
Short-term Debt		2,082
Long-term Debt and Lease Obligation, Current		1,220
Disposal Group, Including Discontinued Operation, Accounts Payable, Current		1,757
Disposal Group, Including Discontinued Operation, Accrued Liabilities, Current		818
Mark-to-market derivative liabilities, current		981
Renewable energy credit obligation		779
Disposal Group, Including Discontinued Operations, Assets, Current - Liabilities held for sale		3
Disposal Group, Including Discontinued Operation, Other Liabilities, Current		300
Current liabilities of discontinued operations		7,940
Long-term Debt, Excluding Current Maturities		4,575
Deferred income taxes and unamortized investment tax credits		3,583
Asset retirement obligations, noncurrent		12,819
Disposal Group, Including Discontinued Operation, Pension Plan Benefit Obligation, Noncurrent		939
Disposal Group, Including Discontinued Operation, Postretirement Plan Benefit Obligation, Noncurrent		876
Spent Nuclear Fuel Obligation, Noncurrent		1,210
Derivative Liability, Noncurrent		513
Other deferred credits and other liabilities		1,161
Long-term debt, deferred credits, and other liabilities of discontinued operations		25,676
Total liabilities		$ 33,616