Financial Information by Business Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Dec. 31, 2025
Segment Reporting [Abstract]
Reportable segments	segments
Segment Reporting Information [Line Items]
Total revenues	$ 5,095	$ 4,798
Other operations and maintenance	940	952
Depreciation and amortization	572	564
Other operating expense	2,406	2,157
Operating Income (Loss)	1,177	1,125
Other Income (deductions)	169	221
Interest Expense	326	331
Allowance for borrowed funds used during construction	(18)	(18)
Income Tax Expense	303	242
Total assets	74,741	70,691	$ 74,603
Capital expenditures	1,155	1,091
CECONY
Segment Reporting Information [Line Items]
Total revenues	4,654	4,441
Depreciation and amortization	539	533
Operating Income (Loss)	1,106	1,067
Other Income (deductions)	144	198
Allowance for borrowed funds used during construction	(16)	(17)
Total assets	69,576		$ 69,316
Operating segment | Con Edison Transmission
Segment Reporting Information [Line Items]
Total revenues	1	1
Other operations and maintenance	3	2
Depreciation and amortization	0	0
Other operating expense	0	0
Operating Income (Loss)	(2)	(1)
Other Income (deductions)	15	16
Interest Expense	0	0
Income Tax Expense	59	5
Total assets	373	481
Capital expenditures	15	14
Operating segment | CECONY
Segment Reporting Information [Line Items]
Total revenues	4,654	4,441
Other operations and maintenance	843	854
Depreciation and amortization	539	533
Other operating expense	2,166	1,987
Operating Income (Loss)	1,106	1,067
Other Income (deductions)	144	198
Interest Expense	302	310
Allowance for borrowed funds used during construction	(16)	(17)
Income Tax Expense	231	227
Total assets	69,576	65,806
Capital expenditures	1,066	992
Operating segment | CECONY | Electric
Segment Reporting Information [Line Items]
Total revenues	2,758	2,686
Other operations and maintenance	649	659
Depreciation and amortization	387	389
Other operating expense	1,388	1,348
Operating Income (Loss)	334	289
Other Income (deductions)	105	154
Interest Expense	210	219
Allowance for borrowed funds used during construction	(12)	(12)
Income Tax Expense	59	37
Total assets	48,656	46,214
Capital expenditures	823	691
Operating segment | CECONY | Gas
Segment Reporting Information [Line Items]
Total revenues	1,464	1,401
Other operations and maintenance	137	139
Depreciation and amortization	122	118
Other operating expense	584	505
Operating Income (Loss)	621	640
Other Income (deductions)	33	32
Interest Expense	77	76
Allowance for borrowed funds used during construction	(4)	(4)
Income Tax Expense	139	159
Total assets	18,361	16,718
Capital expenditures	219	272
Operating segment | CECONY | Steam
Segment Reporting Information [Line Items]
Total revenues	432	354
Other operations and maintenance	57	56
Depreciation and amortization	30	26
Other operating expense	194	134
Operating Income (Loss)	151	138
Other Income (deductions)	6	12
Interest Expense	15	15
Allowance for borrowed funds used during construction	0	(1)
Income Tax Expense	33	31
Total assets	2,559	2,874
Capital expenditures	24	29
Operating segment | O&R
Segment Reporting Information [Line Items]
Total revenues	441	356
Other operations and maintenance	93	95
Depreciation and amortization	33	31
Other operating expense	239	168
Operating Income (Loss)	76	62
Other Income (deductions)	10	12
Interest Expense	20	17
Allowance for borrowed funds used during construction	(2)	(1)
Income Tax Expense	16	13
Total assets	4,552	4,144
Capital expenditures	74	85
Operating segment | O&R | Electric
Segment Reporting Information [Line Items]
Total revenues	282	215
Other operations and maintenance	71	75
Depreciation and amortization	22	21
Other operating expense	163	102
Operating Income (Loss)	26	17
Other Income (deductions)	8	9
Interest Expense	13	11
Allowance for borrowed funds used during construction	(2)	(1)
Income Tax Expense	5	3
Total assets	3,046	2,709
Capital expenditures	53	59
Operating segment | O&R | Gas
Segment Reporting Information [Line Items]
Total revenues	159	141
Other operations and maintenance	22	20
Depreciation and amortization	11	10
Other operating expense	76	66
Operating Income (Loss)	50	45
Other Income (deductions)	2	3
Interest Expense	7	6
Allowance for borrowed funds used during construction	0
Income Tax Expense	11	10
Total assets	1,506	1,435
Capital expenditures	21	26
Other
Segment Reporting Information [Line Items]
Total revenues	(1)	0
Other operations and maintenance	1	1
Depreciation and amortization	0	0
Other operating expense	1	2
Operating Income (Loss)	(3)	(3)
Other Income (deductions)	0	(5)
Interest Expense	4	4
Allowance for borrowed funds used during construction	0
Income Tax Expense	(3)	(3)
Total assets	240	260
Capital expenditures	0	0
Inter-segment
Segment Reporting Information [Line Items]
Total revenues	0	0
Inter-segment | CECONY
Segment Reporting Information [Line Items]
Total revenues	(27)	(27)
Inter-segment | CECONY | Electric
Segment Reporting Information [Line Items]
Total revenues	5	5
Inter-segment | CECONY | Gas
Segment Reporting Information [Line Items]
Total revenues	2	2
Inter-segment | CECONY | Steam
Segment Reporting Information [Line Items]
Total revenues	$ 20	$ 20