Pension Benefits - Total Periodic Benefit Costs (Details) - Pension Benefits - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Defined Benefit Plan Disclosure [Line Items]
Service cost – including administrative expenses	$ 72	$ 85	$ 215	$ 257
Interest cost on projected benefit obligation	126	118	379	353
Expected return on plan assets	(292)	(274)	(876)	(822)
Recognition of net actuarial loss	94	197	283	590
Recognition of prior service credit	(4)	(4)	(12)	(12)
TOTAL PERIODIC BENEFIT COST/(CREDIT)	(4)	122	(11)	366
Cost capitalized	(32)	(41)	(100)	(120)
Reconciliation to rate level	63	(54)	192	(165)
Total credit recognized	27	27	81	81
CECONY | Subsidiaries
Defined Benefit Plan Disclosure [Line Items]
Service cost – including administrative expenses	67	80	202	241
Interest cost on projected benefit obligation	119	111	357	332
Expected return on plan assets	(277)	(260)	(832)	(779)
Recognition of net actuarial loss	89	187	268	559
Recognition of prior service credit	(5)	(5)	(15)	(15)
TOTAL PERIODIC BENEFIT COST/(CREDIT)	(7)	113	(20)	338
Cost capitalized	(30)	(39)	(95)	(113)
Reconciliation to rate level	59	(52)	182	(158)
Total credit recognized	$ 22	$ 22	$ 67	$ 67