Financial Information by Business Segment (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024
Segment Reporting Information [Line Items]
Total revenues	$ 4,530	$ 4,092	$ 12,924	$ 11,587
Other operations and maintenance	967	965	2,840	2,841
Depreciation and amortization	586	550	1,726	1,601
Other operating expense	2,011	986	5,910	4,952
Operating income (loss)	968	862	2,448	2,193
Other Income (deductions)	231	165	693	507
Interest Expense	323	322	971	928
Allowance for borrowed funds used during construction	(14)	(16)	(49)	(45)
Income Tax Expense	202	133	493	307
Total assets	71,844	68,645	71,844	68,645	$ 70,562
Capital expenditures	1,231	1,163	3,586	3,465
CECONY
Segment Reporting Information [Line Items]
Total revenues	4,181	3,762	11,963	10,730
Depreciation and amortization	554	520	1,631	1,512
Operating income (loss)	914	803	2,328	2,107
Other Income (deductions)	201	138	608	436
Allowance for borrowed funds used during construction	(12)	(15)	(45)	(40)
Total assets	66,636		66,636		$ 65,650
Operating segment | Con Edison Transmission
Segment Reporting Information [Line Items]
Total revenues	1	1	3	3
Other operations and maintenance	4	2	8	8
Depreciation and amortization	0	0	1	1
Other operating expense	0	2	0	0
Operating income (loss)	(1)	(1)	(6)	(6)
Other Income (deductions)	16	16	49	46
Interest Expense	0	0	0	0
Income Tax Expense	4	4	12	5
Total assets	505	456	505	456
Capital expenditures	8	9	37	22
Operating segment | CECONY
Segment Reporting Information [Line Items]
Total revenues	4,181	3,762	11,963	10,730
Other operations and maintenance	871	871	2,551	2,539
Depreciation and amortization	554	520	1,631	1,512
Other operating expense	1,842	880	5,453	4,572
Operating income (loss)	914	803	2,328	2,107
Other Income (deductions)	201	138	608	436
Interest Expense	301	300	913	865
Allowance for borrowed funds used during construction	(12)	(15)	(45)	(41)
Income Tax Expense	188	119	462	301
Total assets	66,636	63,849	66,636	63,849
Capital expenditures	1,089	1,082	3,234	3,227
Operating segment | CECONY | Electric
Segment Reporting Information [Line Items]
Total revenues	3,733	3,376	9,000	8,188
Other operations and maintenance	686	686	1,980	1,979
Depreciation and amortization	403	376	1,187	1,090
Other operating expense	1,520	696	4,105	3,608
Operating income (loss)	1,124	998	1,728	1,511
Other Income (deductions)	153	105	466	332
Interest Expense	213	213	644	612
Allowance for borrowed funds used during construction	(7)	(10)	(31)	(28)
Income Tax Expense	256	187	343	191
Total assets	47,820	44,828	47,820	44,828
Capital expenditures	780	756	2,285	2,269
Operating segment | CECONY | Gas
Segment Reporting Information [Line Items]
Total revenues	392	337	2,446	2,119
Other operations and maintenance	132	132	406	407
Depreciation and amortization	122	117	359	343
Other operating expense	260	132	1,080	781
Operating income (loss)	(122)	(112)	601	588
Other Income (deductions)	36	24	105	78
Interest Expense	74	73	226	213
Allowance for borrowed funds used during construction	(5)	(4)	(13)	(12)
Income Tax Expense	(44)	(43)	125	117
Total assets	16,080	16,116	16,080	16,116
Capital expenditures	282	292	867	854
Operating segment | CECONY | Steam
Segment Reporting Information [Line Items]
Total revenues	56	49	517	423
Other operations and maintenance	53	53	165	153
Depreciation and amortization	29	27	85	79
Other operating expense	62	52	268	183
Operating income (loss)	(88)	(83)	(1)	8
Other Income (deductions)	12	9	37	26
Interest Expense	14	14	43	40
Allowance for borrowed funds used during construction	0	(1)	(1)	(1)
Income Tax Expense	(24)	(25)	(6)	(7)
Total assets	2,736	2,905	2,736	2,905
Capital expenditures	27	34	82	104
Operating segment | O&R
Segment Reporting Information [Line Items]
Total revenues	349	329	959	855
Other operations and maintenance	92	92	280	294
Depreciation and amortization	32	30	94	87
Other operating expense	168	104	453	347
Operating income (loss)	57	63	132	127
Other Income (deductions)	11	8	34	24
Interest Expense	18	18	51	48
Allowance for borrowed funds used during construction	(2)	(1)	(4)	(4)
Income Tax Expense	12	12	25	25
Total assets	4,341	3,970	4,341	3,970
Capital expenditures	134	72	315	216
Operating segment | O&R | Electric
Segment Reporting Information [Line Items]
Total revenues	308	293	719	662
Other operations and maintenance	71	71	219	233
Depreciation and amortization	22	21	65	61
Other operating expense	144	83	332	271
Operating income (loss)	71	72	103	97
Other Income (deductions)	8	6	26	19
Interest Expense	12	12	34	31
Allowance for borrowed funds used during construction	(2)	(1)	(4)	(4)
Income Tax Expense	17	17	22	22
Total assets	2,869	2,529	2,869	2,529
Capital expenditures	95	47	218	148
Operating segment | O&R | Gas
Segment Reporting Information [Line Items]
Total revenues	41	36	240	193
Other operations and maintenance	21	21	61	61
Depreciation and amortization	10	9	29	26
Other operating expense	24	21	121	76
Operating income (loss)	(14)	(9)	29	30
Other Income (deductions)	3	2	8	5
Interest Expense	6	6	17	17
Allowance for borrowed funds used during construction			0
Income Tax Expense	(5)	(5)	3	3
Total assets	1,472	1,441	1,472	1,441
Capital expenditures	39	25	97	68
Other
Segment Reporting Information [Line Items]
Total revenues	(1)	0	(1)	(1)
Other operations and maintenance	0	0	1	0
Depreciation and amortization	0	0	0	1
Other operating expense	1	0	4	33
Operating income (loss)	(2)	(3)	(6)	(35)
Other Income (deductions)	3	3	2	1
Interest Expense	4	4	7	15
Allowance for borrowed funds used during construction	0	0		0
Income Tax Expense	(2)	(2)	(6)	(24)
Total assets	362	370	362	370
Capital expenditures	0	0	0	0
Inter-segment
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Inter-segment | CECONY
Segment Reporting Information [Line Items]
Total revenues	(26)	(26)	(79)	(78)
Inter-segment | CECONY | Electric
Segment Reporting Information [Line Items]
Total revenues	5	5	15	15
Inter-segment | CECONY | Gas
Segment Reporting Information [Line Items]
Total revenues	2	2	6	7
Inter-segment | CECONY | Steam
Segment Reporting Information [Line Items]
Total revenues	$ 19	$ 19	$ 58	$ 56