Other Postretirement Benefits - Net Periodic Postretirement Benefit Costs (Details) - Other Postretirement Benefits - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 18	$ 22	$ 21
Interest cost on accumulated other postretirement benefit obligation	35	33	37
Expected return on plan assets	(72)	(68)	(66)
Recognition of net actuarial loss/(gain)	(14)	31	37
Recognition of prior service credit	(1)	(3)	(3)
TOTAL PERIODIC POSTRETIREMENT BENEFIT COST/(CREDIT)	(34)	15	26
Cost capitalized	(8)	(9)	(9)
Reconciliation to rate level	29	(7)	(17)
Total credit recognized	(13)	(1)	0
CECONY
Defined Benefit Plan Disclosure [Line Items]
Service cost	15	16	16
Interest cost on accumulated other postretirement benefit obligation	30	28	31
Expected return on plan assets	(58)	(56)	(54)
Recognition of net actuarial loss/(gain)	(9)	27	36
Recognition of prior service credit	0	(1)	(2)
TOTAL PERIODIC POSTRETIREMENT BENEFIT COST/(CREDIT)	(22)	14	27
Cost capitalized	(7)	(7)	(7)
Reconciliation to rate level	24	(12)	(25)
Total credit recognized	$ (5)	$ (5)	$ (5)