Schedule I - Condensed Financial Information of Parent (Exelon Corporate) - Condensed Balance Sheet (Details) - USD ($) shares in Millions, $ / shares in Millions, $ in Millions		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current assets
Cash and cash equivalents		$ 1,182	$ 663	$ 587	$ 1,349
Accounts receivable
Other accounts receivable, net		1,588	1,398
Regulatory assets, current		1,296	1,228
Other		1,380	1,647
Total current assets		13,957	12,562
Property, plant and equipment, net		84,219	82,584
Deferred debits and other assets
Regulatory assets, noncurrent		8,224	8,759
Other		2,606	3,276
Total deferred debits and other assets		34,837	34,171
Total assets	[1]	133,013	129,317
Current liabilities
Short-term borrowings		3,330	2,031
Long-term debt due within one year		3,373	1,819
Accounts payable		4,136	3,562
Accrued expenses		1,955	2,078
Payables to affiliates, current		5	5
Regulatory liabilities, current		376	581
Other		1,064	1,264
Total current liabilities		16,111	12,771
Long-term debt		35,324	35,093
Deferred credits and other liabilities
Regulatory liabilities, noncurrent		9,628	9,485
Pension obligations		2,990	4,503
Non-pension postretirement benefits obligations		1,687	2,011
Other		2,733	2,942
Total deferred credits and other liabilities		46,393	46,195
Total liabilities	[1]	98,218	94,449
Commitments and contingencies
Shareholders’ equity
Common Stock, No Par Value		$ 0	$ 0
Common Stock, Shares Authorized		2,000	2,000
Common Stock, Shares, Outstanding		979	976
Common stock		$ 20,324	$ 19,373
Treasury Stock, Shares		2	2
Treasury stock, at cost		$ (123)	$ (123)
Retained earnings		16,942	16,735
Accumulated other comprehensive loss, net		(2,750)	(3,400)
Total shareholders’ equity		34,393	32,585
Total liabilities and equity		133,013	129,317
Corporate, Non-Segment [Member]
Current assets
Cash and cash equivalents		295	63
Accounts receivable
Other accounts receivable, net		318	354
Accounts receivable from affiliates, current		35	11
Note receivable from affiliates, current		217	598
Regulatory assets, current		266	315
Other		6	4
Total current assets		1,137	1,345
Property, plant and equipment, net		45	46
Deferred debits and other assets
Regulatory assets, noncurrent		3,164	3,816
Investments in affiliates		44,495	43,149
Deferred income taxes		1,513	1,625
Notes receivable from affiliates, noncurrent		319	324
Other		42	312
Total deferred debits and other assets		49,533	49,226
Total assets		50,715	50,617
Current liabilities
Short-term borrowings		650	500
Long-term debt due within one year		1,150	300
Accounts payable		0	1
Accrued expenses		79	76
Payables to affiliates, current		360	457
Regulatory liabilities, current		3	4
Pension obligations		75	92
Other		7	4
Total current liabilities		2,324	1,434
Long-term debt		6,265	7,418
Deferred credits and other liabilities
Regulatory liabilities, noncurrent		63	32
Pension obligations		7,038	8,351
Non-pension postretirement benefits obligations		116	387
Deferred income taxes		404	348
Other		112	62
Total deferred credits and other liabilities		7,733	9,180
Total liabilities		16,322	18,032
Commitments and contingencies
Shareholders’ equity
Common Stock, No Par Value		$ 0	$ 0
Common Stock, Shares Authorized		2,000	2,000
Common Stock, Shares, Outstanding		979	976
Common stock		$ 20,324	$ 19,373
Treasury Stock, Shares		2	2
Treasury stock, at cost		$ (123)	$ (123)
Retained earnings		16,942	16,735
Accumulated other comprehensive loss, net		(2,750)	(3,400)
Total shareholders’ equity		34,393	32,585
Total liabilities and equity		$ 50,715	$ 50,617

[1] Exelon’s consolidated assets include $2,549 million and $10,200 million as of December 31, 2021 and 2020, respectively, of certain VIEs that can only be used to settle the liabilities of the VIE. Exelon’s consolidated liabilities include $1,077 million and $3,598 million as of December 31, 2021 and 2020, respectively, of certain VIEs for which the VIE creditors do not have recourse to Exelon. See Note 23–Variable Interest Entities for additional information.