Pension Benefits - Schedule of Funded Status (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
CHANGE IN PLAN ASSETS
Fair value of plan assets at beginning of year	$ 524
FAIR VALUE OF PLAN ASSETS AT END OF YEAR	583	$ 524
Pension Benefits
CHANGE IN PROJECTED BENEFIT OBLIGATION
Projected benefit obligation at beginning of year	12,712	12,113	$ 17,357
Service cost – excluding administrative expenses	172	156	283
Interest cost on projected benefit obligation	642	649	505
Net actuarial loss/(gain)	(557)	599	(5,102)
Plan amendments	0	3	0
Benefits paid	(828)	(808)	(930)
PROJECTED BENEFIT OBLIGATION AT END OF YEAR	12,141	12,712	12,113
CHANGE IN PLAN ASSETS
Fair value of plan assets at beginning of year	15,404	14,979	18,504
Actual return on plan assets	724	1,261	(2,583)
Employer contributions	20	21	30
Benefits paid	(828)	(808)	(930)
Administrative expenses	(42)	(49)	(42)
FAIR VALUE OF PLAN ASSETS AT END OF YEAR	15,278	15,404	14,979
FUNDED STATUS	3,137	2,692	2,866
Unrecognized net loss/(gain)	(857)	(757)	(1,485)
Unrecognized prior service credits	(88)	(105)	(124)
Accumulated benefit obligation	11,236	11,739	11,167
CECONY
CHANGE IN PLAN ASSETS
Fair value of plan assets at beginning of year	502
FAIR VALUE OF PLAN ASSETS AT END OF YEAR	560	502
CECONY | Pension Benefits
CHANGE IN PROJECTED BENEFIT OBLIGATION
Projected benefit obligation at beginning of year	11,977	11,395	16,341
Service cost – excluding administrative expenses	162	146	266
Interest cost on projected benefit obligation	604	611	475
Net actuarial loss/(gain)	(557)	572	(4,845)
Plan amendments	0	0	0
Benefits paid	(751)	(747)	(842)
PROJECTED BENEFIT OBLIGATION AT END OF YEAR	11,435	11,977	11,395
CHANGE IN PLAN ASSETS
Fair value of plan assets at beginning of year	14,674	14,248	17,566
Actual return on plan assets	691	1,201	(2,453)
Employer contributions	17	18	17
Benefits paid	(751)	(747)	(842)
Administrative expenses	(40)	(46)	(40)
FAIR VALUE OF PLAN ASSETS AT END OF YEAR	14,591	14,674	14,248
FUNDED STATUS	3,156	2,697	2,853
Unrecognized net loss/(gain)	(825)	(705)	(1,397)
Unrecognized prior service credits	(104)	(124)	(143)
Accumulated benefit obligation	$ 10,554	$ 11,031	$ 10,478