Current Expected Credit Losses - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Increase (decrease) in allowance for uncollectible accounts resulting from COVID-19 pandemic	$ 31	$ 0	$ (47)	$ 19
Subsidiaries | CECONY
Accounts, Notes, Loans and Financing Receivable [Line Items]
Increase (decrease) in allowance for uncollectible accounts resulting from COVID-19 pandemic	$ 30	$ (1)	$ (48)	$ 20