Financial Information by Business Segment (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Segment Reporting Information [Line Items]
Total revenues	$ 2,944	$ 3,415	$ 7,347	$ 7,475
Depreciation and amortization	496	539	994	1,068
Operating income/(loss)	284	387	2,022	1,185
Subsidiaries
Segment Reporting Information [Line Items]
Total revenues	2,744	2,906	6,697	6,423
Depreciation and amortization	470	455	943	900
Operating income/(loss)	262	280	1,071	991
Clean Energy Businesses
Segment Reporting Information [Line Items]
Depreciation and amortization	0	59	0	119
Operating income/(loss)	0	97	37	143
Con Edison Transmission
Segment Reporting Information [Line Items]
Depreciation and amortization	0	0	0	0
Operating income/(loss)	(2)	(2)	(4)	(5)
CECONY | Subsidiaries
Segment Reporting Information [Line Items]
Depreciation and amortization	470	455	943	900
Operating income/(loss)	262	280	1,071	991
CECONY | Electric | Subsidiaries
Segment Reporting Information [Line Items]
Depreciation and amortization	339	338	683	670
Operating income/(loss)	232	220	424	390
CECONY | Gas | Subsidiaries
Segment Reporting Information [Line Items]
Depreciation and amortization	106	93	211	183
Operating income/(loss)	83	100	642	550
CECONY | Steam | Subsidiaries
Segment Reporting Information [Line Items]
Depreciation and amortization	25	24	49	47
Operating income/(loss)	(53)	(40)	5	51
O&R | Subsidiaries
Segment Reporting Information [Line Items]
Depreciation and amortization	26	25	51	48
Operating income/(loss)	11	14	52	59
O&R | Electric | Subsidiaries
Segment Reporting Information [Line Items]
Depreciation and amortization	18	18	36	35
Operating income/(loss)	13	16	14	23
O&R | Gas | Subsidiaries
Segment Reporting Information [Line Items]
Depreciation and amortization	8	7	15	13
Operating income/(loss)	(2)	(2)	38	36
Operating segment
Segment Reporting Information [Line Items]
Total revenues	2,944	3,415	7,347	7,475
Operating segment | Clean Energy Businesses
Segment Reporting Information [Line Items]
Total revenues	0	272	129	532
Operating segment | Con Edison Transmission
Segment Reporting Information [Line Items]
Total revenues	1	1	2	2
Operating segment | CECONY | Subsidiaries
Segment Reporting Information [Line Items]
Total revenues	2,744	2,906	6,697	6,423
Operating segment | CECONY | Electric | Subsidiaries
Segment Reporting Information [Line Items]
Total revenues	2,144	2,240	4,500	4,324
Operating segment | CECONY | Gas | Subsidiaries
Segment Reporting Information [Line Items]
Total revenues	531	582	1,822	1,713
Operating segment | CECONY | Steam | Subsidiaries
Segment Reporting Information [Line Items]
Total revenues	69	84	375	386
Operating segment | O&R | Subsidiaries
Segment Reporting Information [Line Items]
Total revenues	200	238	521	522
Operating segment | O&R | Electric | Subsidiaries
Segment Reporting Information [Line Items]
Total revenues	159	177	341	342
Operating segment | O&R | Gas | Subsidiaries
Segment Reporting Information [Line Items]
Total revenues	41	61	180	180
Inter-segment | CECONY | Subsidiaries
Segment Reporting Information [Line Items]
Total revenues	(25)	(25)	(50)	(50)
Inter-segment | CECONY | Electric | Subsidiaries
Segment Reporting Information [Line Items]
Total revenues	5	5	9	9
Inter-segment | CECONY | Gas | Subsidiaries
Segment Reporting Information [Line Items]
Total revenues	2	2	4	4
Inter-segment | CECONY | Steam | Subsidiaries
Segment Reporting Information [Line Items]
Total revenues	18	18	37	37
Other
Segment Reporting Information [Line Items]
Total revenues	(1)	(2)	(2)	(4)
Depreciation and amortization	0	0	0	1
Operating income/(loss)	$ 13	$ (2)	$ 866	$ (3)