Financial Information by Business Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Segment Reporting Information [Line Items]
Total revenues	$ 4,798	$ 4,280
Other operations and maintenance	952	888
Depreciation and amortization	564	539
Other operating expense	2,157	1,842
Operating income (loss)	1,125	1,011
Other Income (deductions)	221	182
Interest Expense	331	303
Allowance for borrowed funds used during construction	(18)	(14)
Income Tax Expense	242	184
Total assets	70,691	66,680	$ 70,562
Capital expenditures	1,091	1,090
CECONY
Segment Reporting Information [Line Items]
Total revenues	4,441	3,971
Depreciation and amortization	533	510
Operating income (loss)	1,067	989
Other Income (deductions)	198	156
Allowance for borrowed funds used during construction	(17)	(13)
Total assets	65,806		$ 65,650
Operating segment | Con Edison Transmission
Segment Reporting Information [Line Items]
Total revenues	1	1
Other operations and maintenance	2	4
Depreciation and amortization	0	0
Other operating expense	0	0
Operating income (loss)	(1)	(3)
Other Income (deductions)	16	18
Interest Expense	0	0
Income Tax Expense	5	4
Total assets	481	431
Capital expenditures	14	0
Operating segment | CECONY
Segment Reporting Information [Line Items]
Total revenues	4,441	3,971
Other operations and maintenance	854	789
Depreciation and amortization	533	510
Other operating expense	1,987	1,683
Operating income (loss)	1,067	989
Other Income (deductions)	198	156
Interest Expense	310	283
Allowance for borrowed funds used during construction	(17)	(13)
Income Tax Expense	227	181
Total assets	65,806	61,904
Capital expenditures	992	1,022
Operating segment | CECONY | Electric
Segment Reporting Information [Line Items]
Total revenues	2,686	2,441
Other operations and maintenance	659	612
Depreciation and amortization	389	370
Other operating expense	1,348	1,219
Operating income (loss)	289	240
Other Income (deductions)	154	118
Interest Expense	219	201
Allowance for borrowed funds used during construction	(12)	(9)
Income Tax Expense	37	(4)
Total assets	46,214	42,172
Capital expenditures	691	733
Operating segment | CECONY | Gas
Segment Reporting Information [Line Items]
Total revenues	1,401	1,243
Other operations and maintenance	139	128
Depreciation and amortization	118	114
Other operating expense	505	386
Operating income (loss)	640	615
Other Income (deductions)	32	29
Interest Expense	76	69
Allowance for borrowed funds used during construction	(4)	(3)
Income Tax Expense	159	152
Total assets	16,718	16,715
Capital expenditures	272	259
Operating segment | CECONY | Steam
Segment Reporting Information [Line Items]
Total revenues	354	287
Other operations and maintenance	56	49
Depreciation and amortization	26	26
Other operating expense	134	78
Operating income (loss)	138	134
Other Income (deductions)	12	9
Interest Expense	15	13
Allowance for borrowed funds used during construction	(1)	(1)
Income Tax Expense	31	33
Total assets	2,874	3,017
Capital expenditures	29	30
Operating segment | O&R
Segment Reporting Information [Line Items]
Total revenues	356	308
Other operations and maintenance	95	96
Depreciation and amortization	31	29
Other operating expense	168	127
Operating income (loss)	62	56
Other Income (deductions)	12	8
Interest Expense	17	15
Allowance for borrowed funds used during construction	(1)	(1)
Income Tax Expense	13	13
Total assets	4,144	3,747
Capital expenditures	85	68
Operating segment | O&R | Electric
Segment Reporting Information [Line Items]
Total revenues	215	195
Other operations and maintenance	75	75
Depreciation and amortization	21	20
Other operating expense	102	86
Operating income (loss)	17	14
Other Income (deductions)	9	6
Interest Expense	11	10
Allowance for borrowed funds used during construction	(1)	(1)
Income Tax Expense	3	3
Total assets	2,709	2,387
Capital expenditures	59	50
Operating segment | O&R | Gas
Segment Reporting Information [Line Items]
Total revenues	141	113
Other operations and maintenance	20	21
Depreciation and amortization	10	9
Other operating expense	66	41
Operating income (loss)	45	42
Other Income (deductions)	3	2
Interest Expense	6	5
Income Tax Expense	10	10
Total assets	1,435	1,360
Capital expenditures	26	18
Other
Segment Reporting Information [Line Items]
Total revenues	0	0
Other operations and maintenance	1	(1)
Depreciation and amortization	0	0
Other operating expense	2	32
Operating income (loss)	(3)	(31)
Other Income (deductions)	(5)	0
Interest Expense	4	5
Income Tax Expense	(3)	(14)
Total assets	260	598
Capital expenditures	0	0
Inter-segment | CECONY
Segment Reporting Information [Line Items]
Total revenues	(27)	(25)
Inter-segment | CECONY | Electric
Segment Reporting Information [Line Items]
Total revenues	5	4
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	$ 19