Environmental Matters - Schedule of Environmental Remediation Costs (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
|
| Environmental Exit Cost [Line Items] | ||||
| Remediation costs incurred | $ 3 | $ 5 | $ 6 | $ 14 |
| Environmental Remediation Expense, before Recovery, Statement of Income or Comprehensive Income [Extensible Enumeration] | Other Nonoperating Expense | Other Nonoperating Expense | Other Nonoperating Expense | Other Nonoperating Expense |
| CECONY | ||||
| Environmental Exit Cost [Line Items] | ||||
| Remediation costs incurred | $ 3 | $ 4 | $ 6 | $ 13 |
| Environmental Remediation Expense, before Recovery, Statement of Income or Comprehensive Income [Extensible Enumeration] | Other Nonoperating Expense | Other Nonoperating Expense | Other Nonoperating Expense | Other Nonoperating Expense |