Other Postretirement Benefits - Schedule of Funded Status (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
CHANGE IN PLAN ASSETS
Fair value of plan assets at beginning of year	$ 525
FAIR VALUE OF PLAN ASSETS AT END OF YEAR	459	$ 525
CECONY
CHANGE IN PLAN ASSETS
Fair value of plan assets at beginning of year	499
FAIR VALUE OF PLAN ASSETS AT END OF YEAR	439	499
Other Postretirement Benefits
CHANGE IN BENEFIT OBLIGATION
Projected benefit obligation at beginning of year	1,398	1,425	$ 1,357
Service cost	18	22	21
Interest cost on accumulated other postretirement benefit obligation	35	33	37
Net actuarial loss/(gain)	(311)	(13)	74
Benefits paid and administrative expenses, net of subsidies	(130)	(117)	(117)
Participant contributions	48	48	53
PROJECTED BENEFIT OBLIGATION AT END OF YEAR	1,058	1,398	1,425
CHANGE IN PLAN ASSETS
Fair value of plan assets at beginning of year	1,150	1,115	1,026
Actual return on plan assets	(225)	92	142
Employer contributions	13	6	7
Employer group waiver plan subsidies	55	21	20
Participant contributions	48	48	53
Benefits paid	(181)	(132)	(133)
FAIR VALUE OF PLAN ASSETS AT END OF YEAR	860	1,150	1,115
FUNDED STATUS	(198)	(248)	(310)
Unrecognized net loss/(gain)	37	41	115
Unrecognized prior service costs	(12)	(13)	(16)
Other Postretirement Benefits | CECONY
CHANGE IN BENEFIT OBLIGATION
Projected benefit obligation at beginning of year	1,189	1,209	1,154
Service cost	15	16	16
Interest cost on accumulated other postretirement benefit obligation	30	28	31
Net actuarial loss/(gain)	(239)	(3)	63
Benefits paid and administrative expenses, net of subsidies	(121)	(107)	(107)
Participant contributions	47	46	52
PROJECTED BENEFIT OBLIGATION AT END OF YEAR	921	1,189	1,209
CHANGE IN PLAN ASSETS
Fair value of plan assets at beginning of year	955	940	872
Actual return on plan assets	(187)	67	117
Employer contributions	10	3	4
Employer group waiver plan subsidies	50	19	19
Participant contributions	47	46	51
Benefits paid	(167)	(120)	(123)
FAIR VALUE OF PLAN ASSETS AT END OF YEAR	708	955	940
FUNDED STATUS	(213)	(234)	(269)
Unrecognized net loss/(gain)	78	67	114
Unrecognized prior service costs	$ 0	$ 0	$ (1)