Pension Benefits - Total Periodic Benefit Costs (Details) - Pension Benefits - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Defined Benefit Plan Disclosure [Line Items]
Service cost – including administrative expenses	$ 42	$ 46	$ 84	$ 89
Interest cost on projected benefit obligation	170	162	338	321
Expected return on plan assets	(279)	(282)	(558)	(564)
Recognition of net actuarial gain	(67)	1	(133)	(3)
Recognition of prior service credit	(5)	(4)	(9)	(9)
TOTAL PERIODIC BENEFIT CREDIT	(139)	(77)	(278)	(166)
Cost capitalized	(24)	(23)	(45)	(46)
Reconciliation to rate level	(13)	8	(29)	27
Total credit recognized	(176)	(92)	(352)	(185)
CECONY | Subsidiaries
Defined Benefit Plan Disclosure [Line Items]
Service cost – including administrative expenses	40	43	79	84
Interest cost on projected benefit obligation	159	152	318	302
Expected return on plan assets	(267)	(268)	(533)	(538)
Recognition of net actuarial gain	(63)	1	(126)	(4)
Recognition of prior service credit	(5)	(5)	(10)	(10)
TOTAL PERIODIC BENEFIT CREDIT	(136)	(77)	(272)	(166)
Cost capitalized	(22)	(22)	(42)	(43)
Reconciliation to rate level	(14)	5	(30)	21
Total credit recognized	$ (172)	$ (94)	$ (344)	$ (188)