Current Expected Credit Losses - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Increase (decrease) in allowance for uncollectible accounts resulting from COVID-19 pandemic	$ 1	$ (31)	$ (46)	$ (12)
Subsidiaries | CECONY
Accounts, Notes, Loans and Financing Receivable [Line Items]
Increase (decrease) in allowance for uncollectible accounts resulting from COVID-19 pandemic	$ 3	$ (27)	$ (45)	$ (7)