Regulatory Matters - Summary of Utilities Rate Plans (CECONY-Gas) (Details) - CECONY - Gas - Scenario, Forecast	36 Months Ended
	Dec. 31, 2022 USD ($)
Public Utilities, General Disclosures [Line Items]
Percentage of revenue reserve	15.00%
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	$ 63,000,000
Base rate cost recovery period	10 years
Tax credit, amortization period	2 years
Maximum
Public Utilities, General Disclosures [Line Items]
Retention of annual transmission congestion revenues	$ 65,000,000
Year 1
Public Utilities, General Disclosures [Line Items]
Base rate changes	84,000,000
Amortization to income of net regulatory (assets) and liabilities	45,000,000
Potential incentives if performance targets are met	20,000,000
Negative revenue adjustments	81,000,000
Average rate base	7,171,000,000
Year 1 | Electric average excluding AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations	8,123,000,000
Year 1 | AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations	142,000,000
Year 2
Public Utilities, General Disclosures [Line Items]
Base rate changes	122,000,000
Amortization to income of net regulatory (assets) and liabilities	43,000,000
Potential incentives if performance targets are met	22,000,000
Negative revenue adjustments	88,000,000
Average rate base	7,911,000,000
Year 2 | Electric average excluding AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations	8,861,000,000
Year 2 | AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations	183,000,000
Year 3
Public Utilities, General Disclosures [Line Items]
Base rate changes	167,000,000
Amortization to income of net regulatory (assets) and liabilities	10,000,000
Potential incentives if performance targets are met	25,000,000
Negative revenue adjustments	96,000,000
Average rate base	8,622,000,000
Year 3 | Electric average excluding AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations	9,600,000,000
Year 3 | AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations	211,000,000
NYSPSC | Year 1
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount	47,000,000
Base rate, amount of cost recovery	30,000,000
NYSPSC | Year 2
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount	176,000,000
Base rate, amount of cost recovery	37,000,000
NYSPSC | Year 3
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount	170,000,000
Base rate, amount of cost recovery	40,000,000
Annually
Public Utilities, General Disclosures [Line Items]
Income tax benefit to be credited to customers resulting from TCJA	32,000,000
Protected Portion
Public Utilities, General Disclosures [Line Items]
Impact in regulatory liability resulting from TCJA	725,000,000
Protected Portion | Year 1
Public Utilities, General Disclosures [Line Items]
Impact in regulatory liability resulting from TCJA	14,000,000
Protected Portion | Year 2
Public Utilities, General Disclosures [Line Items]
Impact in regulatory liability resulting from TCJA	14,000,000
Protected Portion | Year 3
Public Utilities, General Disclosures [Line Items]
Impact in regulatory liability resulting from TCJA	12,000,000
Unprotected Portion
Public Utilities, General Disclosures [Line Items]
Impact in regulatory liability resulting from TCJA	$ 107,000,000
TCJA regulatory liabilities amortization period	5 years
Unprotected Portion | Annually
Public Utilities, General Disclosures [Line Items]
Impact in regulatory liability resulting from TCJA	$ 21,000,000