Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	$ 3,300	$ 2,773	$ 7,551	$ 6,996
Total revenues	3,220	2,944	7,495	7,347
Other revenues
Disaggregation of Revenue [Line Items]
Total revenues	(80)	171	(56)	351
CECONY
Disaggregation of Revenue [Line Items]
Total revenues	2,996	2,744	6,967	6,697
Operating Segments
Disaggregation of Revenue [Line Items]
Total revenues	3,220	2,944	7,495	7,347
Operating Segments | Clean Energy Businesses
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers			0	82
Total revenues			0	129
Operating Segments | Clean Energy Businesses | Other revenues
Disaggregation of Revenue [Line Items]
Total revenues			0	47
Operating Segments | Clean Energy Businesses | Renewables
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers			0	68
Total revenues			0	68
Operating Segments | Clean Energy Businesses | Renewables | Other revenues
Disaggregation of Revenue [Line Items]
Total revenues			0	0
Operating Segments | Clean Energy Businesses | Energy services
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers			0	7
Total revenues			0	7
Operating Segments | Clean Energy Businesses | Energy services | Other revenues
Disaggregation of Revenue [Line Items]
Total revenues			0	0
Operating Segments | Clean Energy Businesses | Develop/Transfer Projects
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers			0	7
Total revenues			0	7
Operating Segments | Clean Energy Businesses | Develop/Transfer Projects | Other revenues
Disaggregation of Revenue [Line Items]
Total revenues			0	0
Operating Segments | Clean Energy Businesses | Other
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers			0	0
Total revenues			0	47
Operating Segments | Clean Energy Businesses | Other | Other revenues
Disaggregation of Revenue [Line Items]
Total revenues			0	47
Operating Segments | Con Edison Transmission
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1	1	2	2
Total revenues	1	1	2	2
Operating Segments | Con Edison Transmission | Other revenues
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0	0
Operating Segments | CECONY | Subsidiaries
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	3,058	2,577	7,003	6,401
Total revenues	2,996	2,744	6,967	6,697
Operating Segments | CECONY | Other revenues | Subsidiaries
Disaggregation of Revenue [Line Items]
Total revenues	(62)	167	(36)	296
Operating Segments | CECONY | Electric | Subsidiaries
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	2,381	1,991	4,807	4,254
Total revenues	2,370	2,144	4,812	4,500
Operating Segments | CECONY | Electric | Other revenues | Subsidiaries
Disaggregation of Revenue [Line Items]
Total revenues	(11)	153	5	246
Operating Segments | CECONY | Gas | Subsidiaries
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	587	521	1,812	1,779
Total revenues	538	531	1,781	1,822
Operating Segments | CECONY | Gas | Other revenues | Subsidiaries
Disaggregation of Revenue [Line Items]
Total revenues	(49)	10	(31)	43
Operating Segments | CECONY | Steam | Subsidiaries
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	90	65	384	368
Total revenues	88	69	374	375
Operating Segments | CECONY | Steam | Other revenues | Subsidiaries
Disaggregation of Revenue [Line Items]
Total revenues	(2)	4	(10)	7
Operating Segments | O&R | Subsidiaries
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	241	195	546	511
Total revenues	224	200	527	521
Operating Segments | O&R | Other revenues | Subsidiaries
Disaggregation of Revenue [Line Items]
Total revenues	(17)	5	(19)	10
Operating Segments | O&R | Electric | Subsidiaries
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	189	154	379	332
Total revenues	180	159	370	341
Operating Segments | O&R | Electric | Other revenues | Subsidiaries
Disaggregation of Revenue [Line Items]
Total revenues	(9)	5	(9)	9
Operating Segments | O&R | Gas | Subsidiaries
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	52	41	167	179
Total revenues	44	41	157	180
Operating Segments | O&R | Gas | Other revenues | Subsidiaries
Disaggregation of Revenue [Line Items]
Total revenues	(8)	0	(10)	1
Other
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	0	0	0
Total revenues	(1)	(1)	(1)	(2)
Other | Other revenues
Disaggregation of Revenue [Line Items]
Total revenues	$ (1)	$ (1)	$ (1)	$ (2)