Leases - Additional Information (Details) - USD ($) |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
|
| Lessee, Lease, Description [Line Items] | ||||
| Unrecorded unconditional purchase obligation | $ 446,000,000 | $ 446,000,000 | ||
| Right-of-use assets | $ 0 | $ 8,000,000 | ||
| Termination cost | $ 7,000,000 | 0 | $ 7,000,000 | 0 |
| CECONY | ||||
| Lessee, Lease, Description [Line Items] | ||||
| Right-of-use assets | $ 0 | $ 8,000,000 | ||
| CECONY | Lease Expected To Commence In 3 Years With 15 Year Lease Term | ||||
| Lessee, Lease, Description [Line Items] | ||||
| Operating lease, not yet commenced, term of contract (in years) | 15 years | 15 years | ||