Regulatory Matters - Summary of Utilities Rate Plans (CECONY-Electric) (Details) - CECONY - Electric - Scenario, Forecast	36 Months Ended
	Dec. 31, 2022 USD ($)
Public Utilities, General Disclosures [Line Items]
Retention of annual transmission congestion revenues	$ 75,000,000
Weighted average cost of capital (after-tax) (percent)	6.61%
Authorized return on common equity (percent)	8.80%
Earnings sharing (percent)	9.30%
Cost of long-term debt (percent)	4.63%
Common equity ratio (percent)	48.00%
Income tax benefit to be credited to customers resulting from TCJA	$ 377,000,000
Tax credit, amortization period	3 years
Percentage of total consolidated revenues	15.00%
Percentage of debt to total consolidated debt	20.00%
Deferrals for property taxes limitation from rates (percent)	90.00%
Recovery deferral (percent)	80.00%
Maximum deferral (percent)	15.00%
Deferred MTA Power Reliability Costs
Public Utilities, General Disclosures [Line Items]
Amortization to income of net regulatory (assets) and liabilities	$ 238,000,000
Amortization period	5 years
Year 1
Public Utilities, General Disclosures [Line Items]
Base rate changes	$ 113,000,000
Amortization to income of net regulatory (assets) and liabilities	267,000,000
Potential earnings adjustment mechanism incentives	69,000,000
Negative revenue adjustments	450,000,000
Average rate base	21,660,000,000
Base rate, amount of cost recovery	$ 206,000,000
Base rate cost recovery period	10 years
Deferral, annual maximum (not more than) (percent)	0.10%
Year 1 | Electric average excluding AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations	$ 24,572,000,000
Year 1 | Advanced metering infrastructure (AMI)
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations	572,000,000
Year 2
Public Utilities, General Disclosures [Line Items]
Base rate changes	370,000,000
Amortization to income of net regulatory (assets) and liabilities	269,000,000
Potential earnings adjustment mechanism incentives	74,000,000
Negative revenue adjustments	461,000,000
Average rate base	22,783,000,000
Base rate, amount of cost recovery	$ 245,000,000
Deferral, annual maximum (not more than) (percent)	0.075%
Year 2 | Electric average excluding AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations	$ 25,366,000,000
Year 2 | Advanced metering infrastructure (AMI)
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations	740,000,000
Year 3
Public Utilities, General Disclosures [Line Items]
Base rate changes	326,000,000
Amortization to income of net regulatory (assets) and liabilities	272,000,000
Potential earnings adjustment mechanism incentives	79,000,000
Negative revenue adjustments	476,000,000
Average rate base	23,926,000,000
Base rate, amount of cost recovery	$ 251,000,000
Deferral, annual maximum (not more than) (percent)	0.05%
Year 3 | Electric average excluding AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations	$ 26,197,000,000
Year 3 | Advanced metering infrastructure (AMI)
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations	806,000,000
Protected Portion
Public Utilities, General Disclosures [Line Items]
Impact in regulatory liability resulting from TCJA	1,663,000,000
Protected Portion | Year 1
Public Utilities, General Disclosures [Line Items]
Impact in regulatory liability resulting from TCJA	49,000,000
Protected Portion | Year 2
Public Utilities, General Disclosures [Line Items]
Impact in regulatory liability resulting from TCJA	50,000,000
Protected Portion | Year 3
Public Utilities, General Disclosures [Line Items]
Impact in regulatory liability resulting from TCJA	53,000,000
Unprotected Portion
Public Utilities, General Disclosures [Line Items]
Impact in regulatory liability resulting from TCJA	$ 784,000,000
TCJA regulatory liabilities amortization period	5 years
Annually
Public Utilities, General Disclosures [Line Items]
Income tax benefit to be credited to customers resulting from TCJA	$ 126,000,000
Annually | Deferred MTA Power Reliability Costs
Public Utilities, General Disclosures [Line Items]
Amortization to income of net regulatory (assets) and liabilities	48,000,000
Annually | Unprotected Portion
Public Utilities, General Disclosures [Line Items]
Impact in regulatory liability resulting from TCJA	$ 157,000,000