Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	$ 4,279	$ 4,222
Total revenues	4,280	4,403
Other revenues
Disaggregation of Revenue [Line Items]
Total revenues	1	181
CECONY
Disaggregation of Revenue [Line Items]
Total revenues	3,971	3,953
Operating Segments
Disaggregation of Revenue [Line Items]
Total revenues	4,280	4,403
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
Total revenues	1	1
Operating Segments | Con Edison Transmission | Other revenues
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Operating Segments | CECONY | Subsidiaries
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	3,962	3,823
Total revenues	3,971	3,953
Operating Segments | CECONY | Other revenues | Subsidiaries
Disaggregation of Revenue [Line Items]
Total revenues	9	130
Operating Segments | CECONY | Electric | Subsidiaries
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	2,439	2,263
Total revenues	2,441	2,356
Operating Segments | CECONY | Electric | Other revenues | Subsidiaries
Disaggregation of Revenue [Line Items]
Total revenues	2	93
Operating Segments | CECONY | Gas | Subsidiaries
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,229	1,257
Total revenues	1,243	1,291
Operating Segments | CECONY | Gas | Other revenues | Subsidiaries
Disaggregation of Revenue [Line Items]
Total revenues	14	34
Operating Segments | CECONY | Steam | Subsidiaries
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	294	303
Total revenues	287	306
Operating Segments | CECONY | Steam | Other revenues | Subsidiaries
Disaggregation of Revenue [Line Items]
Total revenues	(7)	3
Operating Segments | O&R | Subsidiaries
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	316	316
Total revenues	308	321
Operating Segments | O&R | Other revenues | Subsidiaries
Disaggregation of Revenue [Line Items]
Total revenues	(8)	5
Operating Segments | O&R | Electric | Subsidiaries
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	200	178
Total revenues	195	182
Operating Segments | O&R | Electric | Other revenues | Subsidiaries
Disaggregation of Revenue [Line Items]
Total revenues	(5)	4
Operating Segments | O&R | Gas | Subsidiaries
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	116	138
Total revenues	113	139
Operating Segments | O&R | Gas | Other revenues | Subsidiaries
Disaggregation of Revenue [Line Items]
Total revenues	(3)	1
Other
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	0
Total revenues	0	(1)
Other | Other revenues
Disaggregation of Revenue [Line Items]
Total revenues	$ 0	$ (1)