Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	$ 4,887	$ 4,279
Total revenues	4,798	4,280
Other revenues
Disaggregation of Revenue [Line Items]
Total revenues	(89)	1
CECONY
Disaggregation of Revenue [Line Items]
Total revenues	4,441	3,971
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
Disaggregation of Revenue [Line Items]
Total revenues	4,441	3,971
Operating Segments | CECONY | Subsidiaries
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	4,521	3,962
Total revenues	4,441	3,971
Operating Segments | CECONY | Other revenues | Subsidiaries
Disaggregation of Revenue [Line Items]
Total revenues	(80)	9
Operating Segments | CECONY | Electric
Disaggregation of Revenue [Line Items]
Total revenues	2,686	2,441
Operating Segments | CECONY | Electric | Subsidiaries
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	2,768	2,439
Total revenues		2,441
Operating Segments | CECONY | Electric | Other revenues | Subsidiaries
Disaggregation of Revenue [Line Items]
Total revenues	(82)	2
Operating Segments | CECONY | Gas
Disaggregation of Revenue [Line Items]
Total revenues	1,401	1,243
Operating Segments | CECONY | Gas | Subsidiaries
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,398	1,229
Total revenues		1,243
Operating Segments | CECONY | Gas | Other revenues | Subsidiaries
Disaggregation of Revenue [Line Items]
Total revenues	3	14
Operating Segments | CECONY | Steam
Disaggregation of Revenue [Line Items]
Total revenues	354	287
Operating Segments | CECONY | Steam | Subsidiaries
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	355	294
Total revenues		287
Operating Segments | CECONY | Steam | Other revenues | Subsidiaries
Disaggregation of Revenue [Line Items]
Total revenues	(1)	(7)
Operating Segments | O&R
Disaggregation of Revenue [Line Items]
Total revenues	356	308
Operating Segments | O&R | Subsidiaries
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	365	316
Total revenues	356	308
Operating Segments | O&R | Other revenues | Subsidiaries
Disaggregation of Revenue [Line Items]
Total revenues	(9)	(8)
Operating Segments | O&R | Electric
Disaggregation of Revenue [Line Items]
Total revenues	215	195
Operating Segments | O&R | Electric | Subsidiaries
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	218	200
Total revenues		195
Operating Segments | O&R | Electric | Other revenues | Subsidiaries
Disaggregation of Revenue [Line Items]
Total revenues	(3)	(5)
Operating Segments | O&R | Gas
Disaggregation of Revenue [Line Items]
Total revenues	141	113
Operating Segments | O&R | Gas | Subsidiaries
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	147	116
Total revenues		113
Operating Segments | O&R | Gas | Other revenues | Subsidiaries
Disaggregation of Revenue [Line Items]
Total revenues	$ (6)	$ (3)