Environmental Matters - Environmental Remediation Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Environmental Exit Cost [Line Items]
Remediation costs incurred	$ 13	$ 21
Environmental Remediation Expense, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Expense	Other Nonoperating Expense
CECONY
Environmental Exit Cost [Line Items]
Remediation costs incurred	$ 12	$ 20
Environmental Remediation Expense, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Expense	Other Nonoperating Expense