Material Contingencies - Total Guarantees (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Guarantor Obligations [Line Items]
Total guarantees, by type and term	$ 2,412	$ 2,157
Con Edison Transmission
Guarantor Obligations [Line Items]
Total guarantees, by type and term	407
Energy transactions
Guarantor Obligations [Line Items]
Total guarantees, by type and term	805
Renewable electric projects
Guarantor Obligations [Line Items]
Total guarantees, by type and term	978
Other
Guarantor Obligations [Line Items]
Total guarantees, by type and term	222
0 – 3 years
Guarantor Obligations [Line Items]
Total guarantees, by type and term	1,472
0 – 3 years | Con Edison Transmission
Guarantor Obligations [Line Items]
Total guarantees, by type and term	407
0 – 3 years | Energy transactions
Guarantor Obligations [Line Items]
Total guarantees, by type and term	489
0 – 3 years | Renewable electric projects
Guarantor Obligations [Line Items]
Total guarantees, by type and term	354
0 – 3 years | Other
Guarantor Obligations [Line Items]
Total guarantees, by type and term	222
4 – 10 years
Guarantor Obligations [Line Items]
Total guarantees, by type and term	91
4 – 10 years | Energy transactions
Guarantor Obligations [Line Items]
Total guarantees, by type and term	22
4 – 10 years | Renewable electric projects
Guarantor Obligations [Line Items]
Total guarantees, by type and term	69
4 – 10 years | Other
Guarantor Obligations [Line Items]
Total guarantees, by type and term	0
> 10 years
Guarantor Obligations [Line Items]
Total guarantees, by type and term	849
> 10 years | Con Edison Transmission
Guarantor Obligations [Line Items]
Total guarantees, by type and term	0
> 10 years | Energy transactions
Guarantor Obligations [Line Items]
Total guarantees, by type and term	294
> 10 years | Renewable electric projects
Guarantor Obligations [Line Items]
Total guarantees, by type and term	555
> 10 years | Other
Guarantor Obligations [Line Items]
Total guarantees, by type and term	$ 0