Regulatory Matters - Schedule of Regulatory Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024	Jan. 01, 2024	Jan. 01, 2022
Regulatory Assets [Line Items]
Regulatory assets - noncurrent	$ 5,599.0	$ 5,523.0
Regulatory assets – current	103.0	141.0
Total Regulatory Assets	5,702.0	5,664.0
Regulatory liabilities – noncurrent	5,374.0	5,444.0
Regulatory liabilities—current	249.0	102.0
Total Regulatory Liabilities	5,623.0	5,546.0
Allowance for cost of removal less salvage
Regulatory Assets [Line Items]
Regulatory liabilities – noncurrent	1,686.0	1,527.0
Future income tax
Regulatory Assets [Line Items]
Regulatory liabilities – noncurrent	1,120.0	1,224.0
Unrecognized Other Postretirement Benefit Cost
Regulatory Assets [Line Items]
Regulatory liabilities – noncurrent	873.0	1,054.0
Net unbilled revenue deferrals
Regulatory Assets [Line Items]
Regulatory liabilities – noncurrent	397.0	436.0
Pension and Other Postretirement Employee Benefit Deferrals
Regulatory Assets [Line Items]
Regulatory liabilities – noncurrent	356.0	368.0
Late Payment Charge Deferral
Regulatory Assets [Line Items]
Regulatory liabilities – noncurrent	192.0	231.0
Deferred derivative gains - long term
Regulatory Assets [Line Items]
Regulatory liabilities – noncurrent	119.0	8.0
System benefit charge carrying charge
Regulatory Assets [Line Items]
Regulatory liabilities – noncurrent	108.0	115.0
Storm reserve passback
Regulatory Assets [Line Items]
Regulatory liabilities – noncurrent	80.0	0.0
Settlement of prudence proceeding
Regulatory Assets [Line Items]
Regulatory liabilities – noncurrent	8.0	10.0
Other
Regulatory Assets [Line Items]
Regulatory liabilities – noncurrent	435.0	471.0
Deferred derivative gains
Regulatory Assets [Line Items]
Regulatory liabilities—current	165.0	25.0
Refundable energy costs current
Regulatory Assets [Line Items]
Regulatory liabilities—current	71.0	59.0
Revenue decoupling mechanism liabilities
Regulatory Assets [Line Items]
Regulatory liabilities—current	13.0	18.0
CECONY
Regulatory Assets [Line Items]
Regulatory assets - noncurrent	5,235.0	5,158.0
Regulatory assets – current	95.0	106.0
Regulatory liabilities – noncurrent	4,879.0	4,940.0
Regulatory liabilities—current	205.0	40.0
Subsidiaries | CECONY
Regulatory Assets [Line Items]
Regulatory assets - noncurrent	5,235.0	5,158.0
Regulatory assets – current	95.0	106.0
Total Regulatory Assets	5,330.0	5,264.0
Regulatory liabilities – noncurrent	4,879.0	4,940.0
Regulatory liabilities—current	205.0	40.0
Total Regulatory Liabilities	5,084.0	4,980.0
Subsidiaries | CECONY | Allowance for cost of removal less salvage
Regulatory Assets [Line Items]
Regulatory liabilities – noncurrent	1,468.0	1,322.0
Subsidiaries | CECONY | Future income tax
Regulatory Assets [Line Items]
Regulatory liabilities – noncurrent	1,015.0	1,112.0
Subsidiaries | CECONY | Unrecognized Other Postretirement Benefit Cost
Regulatory Assets [Line Items]
Regulatory liabilities – noncurrent	806.0	984.0
Subsidiaries | CECONY | Net unbilled revenue deferrals
Regulatory Assets [Line Items]
Regulatory liabilities – noncurrent	397.0	436.0
Subsidiaries | CECONY | Pension and Other Postretirement Employee Benefit Deferrals
Regulatory Assets [Line Items]
Regulatory liabilities – noncurrent	313.0	304.0
Subsidiaries | CECONY | Late Payment Charge Deferral
Regulatory Assets [Line Items]
Regulatory liabilities – noncurrent	191.0	224.0
Subsidiaries | CECONY | Deferred derivative gains - long term
Regulatory Assets [Line Items]
Regulatory liabilities – noncurrent	109.0	6.0
Subsidiaries | CECONY | System benefit charge carrying charge
Regulatory Assets [Line Items]
Regulatory liabilities – noncurrent	100.0	110.0
Subsidiaries | CECONY | Storm reserve passback
Regulatory Assets [Line Items]
Regulatory liabilities – noncurrent	80.0	0.0
Subsidiaries | CECONY | Settlement of prudence proceeding
Regulatory Assets [Line Items]
Regulatory liabilities – noncurrent	8.0	10.0
Subsidiaries | CECONY | Other
Regulatory Assets [Line Items]
Regulatory liabilities – noncurrent	392.0	432.0
Subsidiaries | CECONY | Deferred derivative gains
Regulatory Assets [Line Items]
Regulatory liabilities—current	152.0	22.0
Subsidiaries | CECONY | Refundable energy costs current
Regulatory Assets [Line Items]
Regulatory liabilities—current	53.0	18.0
Subsidiaries | CECONY | Revenue decoupling mechanism liabilities
Regulatory Assets [Line Items]
Regulatory liabilities—current	0.0	0.0
System peak reduction and energy efficiency programs
Regulatory Assets [Line Items]
Regulatory assets - noncurrent	1,994.0	1,689.0
System peak reduction and energy efficiency programs | Subsidiaries | CECONY
Regulatory Assets [Line Items]
Regulatory assets - noncurrent	1,893.0	1,601.0
Environmental remediation costs
Regulatory Assets [Line Items]
Regulatory assets - noncurrent	1,079.0	1,038.0
Environmental remediation costs | Subsidiaries | CECONY
Regulatory Assets [Line Items]
Regulatory assets - noncurrent	987.0	952.0
COVID-19 pandemic deferrals
Regulatory Assets [Line Items]
Regulatory assets - noncurrent	1,089.0	1,073.0
COVID-19 pandemic deferrals | Subsidiaries | CECONY
Regulatory Assets [Line Items]
Regulatory assets - noncurrent	1,084.0	1,058.0
Revenue taxes
Regulatory Assets [Line Items]
Regulatory assets - noncurrent	638.0	540.0
Revenue taxes | Subsidiaries | CECONY
Regulatory Assets [Line Items]
Regulatory assets - noncurrent	611.0	517.0
Legacy Meters
Regulatory Assets [Line Items]
Regulatory assets - noncurrent	382.0	413.0
Legacy Meters | Consolidated Edison Company of New York, Inc. And Orange And Rockland Utilities, Inc.
Regulatory Assets [Line Items]
Cost of the program, recovery period			15 years	12 years
Legacy Meters | Subsidiaries | CECONY
Regulatory Assets [Line Items]
Regulatory assets - noncurrent	370.0	398.0
Property tax reconciliation
Regulatory Assets [Line Items]
Regulatory assets - noncurrent	101.0	131.0
Property tax reconciliation | Subsidiaries | CECONY
Regulatory Assets [Line Items]
Regulatory assets - noncurrent	97.0	131.0
Deferred storm costs
Regulatory Assets [Line Items]
Regulatory assets - noncurrent	85.0	147.0
Deferred storm costs | Subsidiaries | CECONY
Regulatory Assets [Line Items]
Regulatory assets - noncurrent	1.0	53.0
Deferred derivative losses - long term
Regulatory Assets [Line Items]
Regulatory assets - noncurrent	18.0	106.0
Deferred derivative losses - long term | Subsidiaries | CECONY
Regulatory Assets [Line Items]
Regulatory assets - noncurrent	15.0	94.0
Unrecognized pension and other postretirement costs
Regulatory Assets [Line Items]
Regulatory assets - noncurrent	4.0	0.0
Unrecognized pension and other postretirement costs | Subsidiaries | CECONY
Regulatory Assets [Line Items]
Regulatory assets - noncurrent	0.0	0.0
MTA power reliability deferral
Regulatory Assets [Line Items]
Regulatory assets - noncurrent	0.0	31.0
MTA power reliability deferral | Subsidiaries | CECONY
Regulatory Assets [Line Items]
Regulatory assets - noncurrent	0.0	31.0
Pension and other postretirement benefits deferrals
Regulatory Assets [Line Items]
Regulatory assets - noncurrent	0.0	2.0
Pension and other postretirement benefits deferrals | Subsidiaries | CECONY
Regulatory Assets [Line Items]
Regulatory assets - noncurrent	0.0	2.0
Other
Regulatory Assets [Line Items]
Regulatory assets - noncurrent	209.0	353.0
Other | Subsidiaries | CECONY
Regulatory Assets [Line Items]
Regulatory assets - noncurrent	177.0	321.0
Deferred derivative losses - short term
Regulatory Assets [Line Items]
Regulatory assets – current	97.0	102.0
Deferred derivative losses - short term | Subsidiaries | CECONY
Regulatory Assets [Line Items]
Regulatory assets – current	90.0	92.0
Recoverable energy costs
Regulatory Assets [Line Items]
Regulatory assets – current	6.0	39.0
Recoverable energy costs | Subsidiaries | CECONY
Regulatory Assets [Line Items]
Regulatory assets – current	5.0	14.0
Arrears Relief Program Deferral | CECONY
Regulatory Assets [Line Items]
Regulatory assets - noncurrent	262.9	323.7
Arrears Relief Program Deferral | O&R
Regulatory Assets [Line Items]
Regulatory assets - noncurrent	$ 0.8	$ 1.4