Financial Information by Business Segment (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024
Segment Reporting Information [Line Items]
Total revenues	$ 3,595	$ 3,220	$ 8,393	$ 7,495
Other operations and maintenance	923	967	1,875	1,856
Depreciation and amortization	576	512	1,140	1,051
Other operating expense	1,741	1,421	3,898	3,257
Operating income (loss)	355	320	1,480	1,331
Other Income (deductions)	241	160	462	342
Interest Expense	318	303	648	605
Allowance for borrowed funds used during construction	(18)	(15)	(36)	(28)
Income Tax Expense	50	(10)	292	174
Total assets	71,501	67,920	71,501	67,920	$ 70,562
Capital expenditures	1,265	1,213	2,356	2,302
CECONY
Segment Reporting Information [Line Items]
Total revenues	3,340	2,996	7,782	6,967
Depreciation and amortization	544	482	1,077	993
Operating income (loss)	347	314	1,414	1,304
Other Income (deductions)	209	142	407	298
Allowance for borrowed funds used during construction	(16)	(13)	(33)	(26)
Total assets	66,565		66,565		$ 65,650
Operating segment | Con Edison Transmission
Segment Reporting Information [Line Items]
Total revenues	1	1	2	2
Other operations and maintenance	4	3	7	6
Depreciation and amortization	0	0	0	1
Other operating expense	0	0	0	0
Operating income (loss)	(3)	(2)	(5)	(5)
Other Income (deductions)	17	11	33	30
Interest Expense	0	0	0	0
Income Tax Expense	4	(4)	8	0
Total assets	490	441	490	441
Capital expenditures	15	13	29	13
Operating segment | CECONY
Segment Reporting Information [Line Items]
Total revenues	3,340	2,996	7,782	6,967
Other operations and maintenance	826	871	1,680	1,659
Depreciation and amortization	544	482	1,077	993
Other operating expense	1,623	1,329	3,611	3,011
Operating income (loss)	347	314	1,414	1,304
Other Income (deductions)	209	142	407	298
Interest Expense	302	282	612	566
Allowance for borrowed funds used during construction	(16)	(13)	(33)	(26)
Income Tax Expense	48	1	275	182
Total assets	66,565	63,075	66,565	63,075
Capital expenditures	1,154	1,124	2,146	2,145
Operating segment | CECONY | Electric
Segment Reporting Information [Line Items]
Total revenues	2,581	2,370	5,267	4,812
Other operations and maintenance	636	671	1,295	1,284
Depreciation and amortization	396	345	784	715
Other operating expense	1,237	1,082	2,586	2,301
Operating income (loss)	312	272	602	512
Other Income (deductions)	159	108	313	226
Interest Expense	212	199	431	400
Allowance for borrowed funds used during construction	(11)	(9)	(23)	(18)
Income Tax Expense	51	8	88	4
Total assets	46,885	43,356	46,885	43,356
Capital expenditures	814	779	1,505	1,512
Operating segment | CECONY | Gas
Segment Reporting Information [Line Items]
Total revenues	653	538	2,055	1,781
Other operations and maintenance	134	147	273	274
Depreciation and amortization	119	112	237	226
Other operating expense	314	194	819	580
Operating income (loss)	86	85	726	701
Other Income (deductions)	37	25	69	54
Interest Expense	75	70	152	140
Allowance for borrowed funds used during construction	(5)	(4)	(9)	(7)
Income Tax Expense	11	9	169	160
Total assets	16,749	16,631	16,749	16,631
Capital expenditures	314	304	586	563
Operating segment | CECONY | Steam
Segment Reporting Information [Line Items]
Total revenues	106	88	460	374
Other operations and maintenance	56	53	112	101
Depreciation and amortization	29	25	56	52
Other operating expense	72	53	206	130
Operating income (loss)	(51)	(43)	86	91
Other Income (deductions)	13	9	25	18
Interest Expense	15	13	29	26
Allowance for borrowed funds used during construction	0	0	(1)	(1)
Income Tax Expense	(14)	(16)	18	18
Total assets	2,931	3,088	2,931	3,088
Capital expenditures	26	41	55	70
Operating segment | O&R
Segment Reporting Information [Line Items]
Total revenues	254	224	610	527
Other operations and maintenance	93	94	188	191
Depreciation and amortization	31	29	62	58
Other operating expense	117	92	285	214
Operating income (loss)	13	9	75	64
Other Income (deductions)	11	8	23	16
Interest Expense	17	15	34	30
Allowance for borrowed funds used during construction	(2)	(2)	(3)	(2)
Income Tax Expense	1	0	14	13
Total assets	4,124	3,810	4,124	3,810
Capital expenditures	96	76	181	144
Operating segment | O&R | Electric
Segment Reporting Information [Line Items]
Total revenues	196	180	411	370
Other operations and maintenance	73	75	148	151
Depreciation and amortization	22	20	43	40
Other operating expense	85	73	187	154
Operating income (loss)	16	12	33	25
Other Income (deductions)	8	6	17	13
Interest Expense	11	10	22	19
Allowance for borrowed funds used during construction	(2)	(2)	(3)	(2)
Income Tax Expense	3	2	6	5
Total assets	2,719	2,427	2,719	2,427
Capital expenditures	64	52	122	101
Operating segment | O&R | Gas
Segment Reporting Information [Line Items]
Total revenues	58	44	199	157
Other operations and maintenance	20	19	40	40
Depreciation and amortization	9	9	19	18
Other operating expense	32	19	98	60
Operating income (loss)	(3)	(3)	42	39
Other Income (deductions)	3	2	6	3
Interest Expense	6	5	12	11
Income Tax Expense	(2)	(2)	8	8
Total assets	1,405	1,383	1,405	1,383
Capital expenditures	32	24	59	43
Other
Segment Reporting Information [Line Items]
Total revenues	0	(1)	(1)	(1)
Other operations and maintenance	0	(1)	0	0
Depreciation and amortization	1	1	1	(1)
Other operating expense	1	0	2	32
Operating income (loss)	(2)	(1)	(4)	(32)
Other Income (deductions)	4	(1)	(1)	(2)
Interest Expense	(1)	6	2	9
Income Tax Expense	(3)	(7)	(5)	(21)
Total assets	322	594	322	594
Capital expenditures	0	0	0	0
Inter-segment | CECONY
Segment Reporting Information [Line Items]
Total revenues	(26)	(26)	(53)	(52)
Inter-segment | CECONY | Electric
Segment Reporting Information [Line Items]
Total revenues	5	5	10	10
Inter-segment | CECONY | Gas
Segment Reporting Information [Line Items]
Total revenues	2	3	5	5
Inter-segment | CECONY | Steam
Segment Reporting Information [Line Items]
Total revenues	$ 19	$ 18	$ 38	$ 37