Regulatory Matters - Regulatory Assets (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024	Jan. 01, 2024	Jan. 01, 2022
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	$ 5,554.0	$ 5,523.0
Regulatory assets – current	118.0	141.0
Total Regulatory Assets	5,672.0	5,664.0
Energy efficiency and other clean energy programs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	1,772.0	1,675.0
Customer account deferrals
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	1,178.0	1,073.0
Environmental investigation and remediation costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	1,024.0	1,038.0
Revenue taxes
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	616.0	540.0
Legacy meters
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	390.0	413.0
Property tax reconciliation
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	111.0	131.0
Deferred storm costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	88.0	147.0
Deferred derivative losses - long term
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	64.0	106.0
Unrecognized pension and other postretirement costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	21.0	0.0
MTA power reliability deferral
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	8.0	31.0
Pension and other postretirement benefits deferrals
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	0.0	2.0
Other
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	282.0	367.0
Deferred derivative losses - short term
Regulatory Assets [Line Items]
Regulatory assets – current	116.0	102.0
Recoverable energy costs
Regulatory Assets [Line Items]
Regulatory assets – current	2.0	39.0
CECONY
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	5,197.0	5,158.0
Regulatory assets – current	110.0	106.0
CECONY \| Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	5,197.0	5,158.0
Regulatory assets – current	110.0	106.0
Total Regulatory Assets	5,307.0	5,264.0
CECONY \| Energy efficiency and other clean energy programs \| Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	1,680.0	1,601.0
CECONY \| Customer account deferrals \| Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	1,169.0	1,058.0
CECONY \| Environmental investigation and remediation costs \| Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	937.0	952.0
CECONY \| Revenue taxes \| Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	589.0	517.0
CECONY \| Legacy meters \| Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	377.0	398.0
CECONY \| Property tax reconciliation \| Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	109.0	131.0
CECONY \| Deferred storm costs \| Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	10.0	53.0
CECONY \| Deferred derivative losses - long term \| Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	57.0	94.0
CECONY \| Unrecognized pension and other postretirement costs \| Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	13.0	0.0
CECONY \| MTA power reliability deferral \| Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	8.0	31.0
CECONY \| Pension and other postretirement benefits deferrals \| Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	0.0	2.0
CECONY \| Other \| Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	248.0	321.0
CECONY \| Deferred derivative losses - short term \| Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – current	108.0	92.0
CECONY \| Recoverable energy costs \| Subsidiaries
Regulatory Assets [Line Items]
Regulatory assets – current	2.0	14.0
CECONY \| Arrears Relief Program Deferral
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	279.3	323.7
O&R \| Arrears Relief Program Deferral
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	$ 1.2	$ 1.4
Consolidated Edison Company of New York, Inc. And Orange And Rockland \| Legacy meters
Regulatory Assets [Line Items]
Cost of the program, recovery period (in years)			15 years	12 years

CONSOLIDATED EDISON INC 10-Q