Summary of Significant Accounting Policies and Other Matters - Schedule of Investments (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021	May 31, 2021	Dec. 31, 2019
Schedule of Equity Method Investments [Line Items]
Supplemental retirement income plan assets	$ 459	$ 525
Deferred income plan assets	93	102
Other	2	3
INVESTMENTS	$ 841	853
NY Transco | Payment Guarantee by CET Electric of Contributions to New York Transco LLC
Schedule of Equity Method Investments [Line Items]
Ownership interest, percentage	45.70%
CECONY
Schedule of Equity Method Investments [Line Items]
Supplemental retirement income plan assets	$ 439	499
Deferred income plan assets	93	102
Other	7	7
INVESTMENTS	539	608
Mountain Valley Pipeline
Schedule of Equity Method Investments [Line Items]
Equity method investment	530	530
Mountain Valley Pipeline | CET Gas
Schedule of Equity Method Investments [Line Items]
Equity method investment				$ 530
Aggregate project cost			$ 6,600
Mountain Valley Pipeline | Con Edison Transmission
Schedule of Equity Method Investments [Line Items]
Equity method investment	111	111
Mountain Valley Pipeline | Con Edison Transmission | CECONY
Schedule of Equity Method Investments [Line Items]
Equity method investment	0	0
New York Transco, LLC | Con Edison Transmission
Schedule of Equity Method Investments [Line Items]
Equity method investment	176	112
New York Transco, LLC | Con Edison Transmission | CECONY
Schedule of Equity Method Investments [Line Items]
Equity method investment	$ 0	$ 0