Income Tax - Schedule of Components of Income Tax (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
State
Current	$ 5	$ 14	$ 7
Deferred	324	79	50
Federal
Current	58	43	(2)
Deferred	117	61	42
Amortization of investment tax credits	(6)	(7)	(7)
Total income tax expense	498	190	90
CECONY
State
Current	0	1	6
Deferred	110	106	97
Federal
Current	170	121	41
Deferred	(23)	21	73
Amortization of investment tax credits	(2)	(3)	(2)
Total income tax expense	$ 255	$ 246	$ 215