Financial Information by Business Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Segment Reporting Information [Line Items]
Total revenues	$ 4,403	$ 4,060
Depreciation and amortization	499	529
Operating income/(loss)	1,739	799
Subsidiaries
Segment Reporting Information [Line Items]
Total revenues	3,953	3,517
Depreciation and amortization	473	446
Operating income/(loss)	809	711
Clean Energy Businesses
Segment Reporting Information [Line Items]
Depreciation and amortization	0	59
Operating income/(loss)	36	46
Con Edison Transmission
Segment Reporting Information [Line Items]
Depreciation and amortization	0	0
Operating income/(loss)	(2)	(3)
CECONY | Subsidiaries
Segment Reporting Information [Line Items]
Depreciation and amortization	473	446
Operating income/(loss)	809	711
CECONY | Electric | Subsidiaries
Segment Reporting Information [Line Items]
Depreciation and amortization	343	332
Operating income/(loss)	194	170
CECONY | Gas | Subsidiaries
Segment Reporting Information [Line Items]
Depreciation and amortization	105	90
Operating income/(loss)	559	451
CECONY | Steam | Subsidiaries
Segment Reporting Information [Line Items]
Depreciation and amortization	25	24
Operating income/(loss)	56	90
O&R | Subsidiaries
Segment Reporting Information [Line Items]
Depreciation and amortization	25	24
Operating income/(loss)	41	46
O&R | Electric | Subsidiaries
Segment Reporting Information [Line Items]
Depreciation and amortization	18	17
Operating income/(loss)	1	8
O&R | Gas | Subsidiaries
Segment Reporting Information [Line Items]
Depreciation and amortization	7	7
Operating income/(loss)	40	38
Operating segment
Segment Reporting Information [Line Items]
Total revenues	4,403	4,060
Operating segment | Clean Energy Businesses
Segment Reporting Information [Line Items]
Total revenues	129	260
Operating segment | Con Edison Transmission
Segment Reporting Information [Line Items]
Total revenues	1	1
Operating segment | CECONY | Subsidiaries
Segment Reporting Information [Line Items]
Total revenues	3,953	3,517
Operating segment | CECONY | Electric | Subsidiaries
Segment Reporting Information [Line Items]
Total revenues	2,356	2,084
Operating segment | CECONY | Gas | Subsidiaries
Segment Reporting Information [Line Items]
Total revenues	1,291	1,131
Operating segment | CECONY | Steam | Subsidiaries
Segment Reporting Information [Line Items]
Total revenues	306	302
Operating segment | O&R | Subsidiaries
Segment Reporting Information [Line Items]
Total revenues	321	285
Operating segment | O&R | Electric | Subsidiaries
Segment Reporting Information [Line Items]
Total revenues	182	166
Operating segment | O&R | Gas | Subsidiaries
Segment Reporting Information [Line Items]
Total revenues	139	119
Other
Segment Reporting Information [Line Items]
Total revenues	(1)	(3)
Depreciation and amortization	1	0
Operating income/(loss)	855	(1)
Inter-segment | CECONY | Subsidiaries
Segment Reporting Information [Line Items]
Total revenues	(25)	(25)
Inter-segment | CECONY | Electric | Subsidiaries
Segment Reporting Information [Line Items]
Total revenues	5	4
Inter-segment | CECONY | Gas | Subsidiaries
Segment Reporting Information [Line Items]
Total revenues	2	2
Inter-segment | CECONY | Steam | Subsidiaries
Segment Reporting Information [Line Items]
Total revenues	$ 18	$ 19