Accounts Receivable - Purchases and Sales of Accounts Receivable (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Mar. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Cash proceeds received	$ 200			$ 400
Loss on sale of receivables	69	$ 36	$ 30
Proceeds from new transfers	6,108	6,095	2,816
Cash collections received on DPP and reinvested in the Facility	4,764	3,502	3,771
Cash collections reinvested in the Facility	10,872	9,597	6,587
Total receivables sold	423	147	824
Exelon Utility Registrants Affiliates
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivables sold to Exelon's utility subsidiaries prior to the separation on February 1, 2022	4	23	$ 252
Sale of Accounts Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Derecognized receivables transferred at fair value	1,615	1,265
Cash proceeds received	1,100	900
DPP	515	365
Customer accounts receivable sold into the Facility	$ 11,274	$ 9,747